Ragusa (Dubrovnik), a city-state on the eastern Adriatic coast has organized one of the first intelligence organizations in history. Having no army Ragusa's indipendence depended heavily on accurate and timely intelligence gathered by its merchant, diplomats and scientists. Througout its history as a indipendent city-state (from 14th to 19th century) Ragusa maintained its neutral position and ballanced between Austria, Venice, Otoman Empire and other European powers having good diplomatic and trade relations with all of them. The author's own research of the Dubrovnik's archive show that good intelligence was critical for such a policy enabling Ragusa's diplomats quick adapting to the new situations and helping them "guessing right", and that is exactly what intelligence is.
A Surprising Discovery
In l972, while questioning why Communist politicians - Tito in particular - failed to develop their countries to full potential, I concluded that they failed because they suffered an "information deficiency." Governments need information to survive; that is, the gathering, classification, and analysis of data. Governments now operate in the tenth Intelligence Revolution, one induced by the democratic capitalist system. Former CIA director, William Colby, set out the revolution's components:
- National and International (i.e. NATO) Intelligence and Security (I&S) communities.
- Oversight and control bodies.
- Science-based technologies.
- Privatization of Intelligence; that is, corporations base their RISS according to IBM
- Future I&S function: population self-management
- To which can be added:
- Individualization: mass education, electronic media stimulating inquisitiveness and creativity of individuals and social systems.
- Emergence of the "bridge-building" methods of science.
I&S has a past, but little written history. Unaware of emerging global trends, historians generally ignored the I&S past. One, however, knew better. T. Browald of Sweden's Handelsbank, wrote in The Way Ahead (l975) that "Three institutions in history had the best intelligence: the British Empire, the Swiss banks, and the Catholic Church". However, one can add to these the tiny republic of Ragusa, which, amid great powers often in conflict, lived free for five centuries using a well-organized I&S system.
Ragusa was the name used for the Republic of Dubrovnik up to 1806. The Croat name Dubrovnik appeared first in a 12th century document, but it was not generally used in European languages.
Ragusa in its world
Similar to Amalfi, Genoa, Pisa, Florence, and Venice, Ragusa was a commercial city-state living by "intellegentia pecuniae querendo."1 In the 7th century, when the Avars and Slavs destroyed the Greek-Roman city of Epidaurus, some refugees settled on a nearby rock ("laus" in Greek) which became over time Raus, Rausia, and finally Ragusa. E. Carter, in his monumental Dubrovnik (Ragusa): A Classic City-State (l975) shows that Ragusa from its inception survived on shipbuilding and trade, exporting wax, wool, and skins from the Balkans, and textiles, wheat, and luxury items from the Mediterranean.
By l400, 8,000 inhabitants lived within its walls, today the same 400 meters in diameter. Ragusans, now rich by trade, purchased from the ruling princes an 80 kilometer strip of land along the coast, having about 40,000 inhabitants. Until l190, Ragusa had a Byzantine governor, and then a Venetian. From l358 to l806, Ragusa (managed by I&S) showed "Libertas" on its flag, the only Dalmatian town free of Venice.
Ragusa's government system was so similar to Venice's that it was called "scimia di Venezia"(a monkey irritating Venice).2 Venice's protector was San Marco, and Ragusa's Saint Blaise. Its architecture and art were Italian, its official languages Latin, then Italian. Like Venice, Ragusa was governed by a prince, with a Great Council, Senate, and a Minor (Executive) Council, all chosen from aristocratic families, limited in number in 1297 in Venice, and in Ragusa in l332. In 1359, Ragusa decentralized its government; a rector limited in power was elected for a month; to keep them apolitical, its bishop and Council secretary were imported. All government officials were elected by the Grand Council, numbering l30 nobles in l358, twenty in 1806.
The Ragusan Archives document , "Speculum Maioris Consilii Rectores", showed 4397 rectors elected between September 1440 to June l806; 2764, (63 %) were from eleven "old patrician" families: Gozze, Bona, Caboga, Cerva, Ghetaldi, Giorgi, Gradi, Pozza, Saraca, Sorgo, and Zamanya. An 1802 list of Ragusa's governing bodies showed3 that 6 of the 8 Minor Council, and 15 of 20 Grand Council members were from the same 11 families.
Paradoxically, the armed powers at the time - Serbia, Croatia, Austro-Hungary, Venice, Spain, the Vatican, and, from l400 on, Turkey, France, England, and Russia, were often in conflict or at war with one another, but they comprised unarmed Ragusa's world trading partners.
Its Governing Doctrine
"'For example' is no proof"
Ragusa prospered free in that world because its ruling families' governing doctrines were based on its unique culture. Nikola Vito Gozze, who served seven times as the rector of Ragusa, in his Dello Stato delle Republiche, Venice , l591, lists 222 governing rules; the following are typical:
- It is better that a republic be governed by laws than by men
- A prince by election is better than one by succession
- Citizens of moderate means better love their Princes and country than the rich, who refuse to have anyone above them.
- To govern a republic, it is best to imitate the great god of nature, who does everything little by little, almost unobserved
Above the door of the Senate chamber in the Prince's palace stands engraved "Obliti privatorum publica curate"(Forget private interests (as you) manage public ones"). So until 1806, the republic had only three monuments to Ragusans. A stone tablet on the Municipal building honors Nikola Bono, Ragusa's ambassador to Istanbul, who in l678 died in prison for "our country's freedom" rather than to surrender to a Sultan's demands. In the Prince's palace, there is the l638 statue of Miho Pracat, a merchant and generous benefactor of Ragusa. The third individual rewarded with a monument is Rudjer Boskovic. With "the consent of the Senate", a large marble table was placed in the cathedral a few months after his death in 1787, praising his scientific achievements and "his help to the Republic"; he left at age 15, 'promoting its interests', including in intelligence."
Talleyrand, France's foreign minister, defined Ragusa's govrning policy (1806) as "Too weak to defend itself, Ragusa always looked for foreign protectors. Its system consisted of bending to the will of the strong and passing through political events without participating in them." In I servizi Segreti di Venezia (1994) P. Preto describes Ragusa as "Door to the Orient for Christians, to the West for the Turks; faithful daughter of the Roman church, and friend of Catholic Spain; vassal of the Sultan, impartial distributor of news to friends and enemies, and "doublespy" of the Turks and Christians." Ragusa's policy was "to have no friends or enemies, only its own interests." (Lord Palmerston,19th century.) Thus, P. Ricault, in his History of the Ottoman Empire (l670) described Ragusa as "a follower of seven flags ." The alleged saying "non siamo Christiani non siamo Giudei, ma poveri Ragusei" is probably a Venetian invention.
In the wars and conflicts among its neighboring powers, Ragusa remained totally neutral; in the l570 Lepanto battle, Ragusa boats served on both sides. History records that "Ragusa defended itself by diplomacy." But Ragusa's diplomacy took unusual forms; consider these written instructions by the Ragusa government (1568) to its ambassadors heading to Istanbul: "When the pasha tells you that the Sultan wants to increase our tribute, fall on your knees, pour tears, and with most humble words beg him to desist, for we have always been his good servant." But the Ambassadors were also instructed to give the pasha a bribe of 5000 ducats to support their tearful pleas."4
Historians have constantly underestimated the I&S role in Ragusa's history. To survive in a hostile world, Ragusa, small and unarmed, developed an unparalleled I&S system . This paper is a long footnote updating the excellent Ragusa (i.e., Dubrovnik) histories of L. Vojnovic, I. Foretic, I. Mitic, Novak, Beretic, Sundrica and others. I hope to illustrate (if not prove) the hypothesis that few states in history had more effective intelligence and security system than the Ragusa republic; the proof is its ability to remain free by skillfully adapting and by "guessing right"; i.e., what intelligence is.
Ragusa Intelligence & Security System (RISS)
"Every statement I make must be understood as a question"
The document, "Reformationes" (Ragusa/Dubrovnik Archives) records in Latin the birth of the first Intelligence and Security service in Europe.5
On August 12, l301, the Senate decided to choose able men to be responsible for the fortification and security of the city of Ragusa as they see fit and appropriate. The Senate also decided to choose in the same way good and competent men to explore where they consider best, both inside and outside Ragusa's republic, all information and to inform his lordship the prince as necessary for the good and prosperity of the state.
The men responsible for these tasks were named and so survive in Ragusa's history.
Fortification and security:
For gathering news and information
I&S Organization and Process
How was the Ragusa Intelligence function organized, its personnel selected; how and from what sources was information gathered and analysed; how were the results used by its government and diplomats, and at what cost; was it kept secret from the Venice governor until l358; what techniques were used? On Feb 12, l348, the Senate ordered the Minor Council to assign five "sapientes ad inquerandum et inestandum de novis" (five knowledgable men for inquiry and confirmation of news) to gather intelligence from Southern Italy and Sclavonia (Serbia). On Sepember 20, l348, the Senate elected 5 "pasatores" 6, one outside and four inside the city. In l737, a battle was fought between the Austro-Hungarians and Turks at the town of Banja Luka in Bosnia. The action precipitated the following letter:
The Prince and the Counsellors of the Republic
To the magnificent don Vicko Mrshe
our always beloved
Dubrovniik, 22 August, l737
Our public service requires to have exact and detailed information on all questions in the appended letter. In order to have them exact and without a doubt, it is necessary that you personally go to Ravno and record them there with prince Ivich who, we are informed, was in the battle near Banja Luka and has now returned home. You should confidentially question him on all the listed queries and on everything else he knows. You must strive to learn every detail you consider important for us. If somebody else has returned from the army that you know, also gather information from him in order to increase your knowledge with the exactness you always use. Everything you come to know will be received with special satisfaction. We recommend you act quickly so that we can get the information on all the listed questions in our letter. Nothing of this would be useful without the caution you always show with your own special style. Nothing more, but our greetings.
The list consisted of about l20 questions: for example, "How many soldiers were there on the Bosnian side? How many Turks, and how many Raya( non-Turks)? How many from Bosnia; How many from Hercegovina? Who commanded the one and the other? Who was the supreme commander? When did they come? Where were the Austrians (Germans in the text)? If the Germans were at Banja Luka, in how many camps? Were both on one side of the river or on both?"
The Archives contain many such questionnaires that Ragusa sent to its "beloved" informers such as don Mrshe.
From its earliest days up to l806, the Ragusa government, always vigilant, was particularly attentive to its security and intelligence. Its first walls enabled it to resist a siege by Arab pirates in 880. After l359, it began building its present walls, described by I. Beretic: "During the eleven centuries of its existence, the small Ragusa (Dubrovnik) republic paid special attention to the fortification of its towns and territories. Its fortifications were built not only for the protection of towns from enemy sieges, but for the defense of its peasants from robbery by the neighboring feudal lords and pirates." Beretic describes in detail who was responsible, how the labor force was recruited, and where materials were obtained. Ragusans, aware of the invention of artillery, built the magnificent Mincheta and Lovrenac towers and mounted several hundred cannons on the walls..
The foundation of Ragusa's security was eternal vigilance and close analysis of every situation. The method is described by Senator Junius Resti in his Chronica Ragusina: Ab Origine Urbis usque ad Annum 1451:7 "In the political government of states and especially of republics governed by old families, the basic principle has always been not to ignore anything suspect and with caution to proceed to the bottom of every case, in order to find the appropriate remedies and arrive at one's real interests securely and with good results." Such vigilance resulted in counterintelligence operations; Resti again: "In l529, Francesco Silvana of Macerate, for many years secretary of the Republic of Ragusa , was tried for treason in an important case and garrotted in prison." Ragusa also used other means. On April l3, l665(?), the Senate of the Republic, by a 35-0 vote, approved the use of poisons obtained from Florence. Soon after, the Ragusa Italian bishop suddenly died, and was mourned by the Senate..
Ragusa's "Eyes and Ears"
Such analysis as described by Resti was certainly based on information from all parts of Ragusa's world, using its human and technical "eyes and ears"8. My summary exploration of the Archives showed that Ragusa used the following "eyes and ears":
As described by I.Mitich, Ragusa had its first consul in Brskovo, Italy in l250; by l589 it had 44: 40 in Italy, 3 in Spain, and 1 in France. The Archives contain literally thousands of communications between the government of Dubrovnik and its consuls; for example, on September 9, l698, the Senate thanks L. Barca, the consul in Istanbul, for news on peace negotiations, and asks for additional information. On May11, l700, the Senate asks its consul in Durazzo, Albania, why Turkish troops are being assembled and where they will be sent. Zivojinovich writes ( see bibliography) that in l780 "Dubrovnik diplomats and consuls had well informed, and had sent to the Senate detailed reports related to the war between Britain and its American colonies."
One of the most interesting consular reports to the Senate was from "F. Favi, Agente", sent in Paris (July 23, l783). It writes: "The predictions of the best informed politicians are beginning to be fulfilled; that once free, America would absorb Europe. For there is considerable emigration in that direction. Already it is estimated that ten thousand Germans have left from Hamburg, Holland, and Ostend to settle there. An English and Hamburg merchant company has sent three boats to America, full of German emigrants." Favi gives statistics on the kinds of individuals who are emigrating to America and why. They are skilled in a variety of professions and dissatisfied with European political and economic conditions. His report is an example of the best kind of intelligence, defined by Aristotle in his Nichomachian Ethics 330 BC., as "the capability to perceive meaning in detailed information".
From documents in the Archives, I. Mitich concludes that "The Dubrovnik consuls sent up to date, precise, and relevant information about political, military, and commerial situations. On the basis of such reports, the government of Dubrovnik (Ragusa) could make the required decisions and take positions in specific conflicts to maintain its neutrality and thus advance its commercial interests".
Ragusa had trade colonies in many towns in nearby Bosnia, Istanbul, and Sofia. Among the most important was that in Belgrade. The merchants there were the "eyes and ears" of the Ragusa government. Thus, on October 28, l558, the Ragusa government informed the king of Spain that "Our agents in Belgrade write that his Highness, the Grand Turk, is preparing for war in Hungary to start next Spring. Thus we learn that all local governors have been ordered to prepare food and other materials and assemble them in Belgrade." The merchants from the affected colonies informed Ragusa that the Belgrade Ragusa merchants (in a letter of November 15, 1681) agreed to buy skins jointly at the same price, because of a shortage (see Figure 1).
Nobles of l8 years of age and older were elected as village chiefs. Dozens of messages were exchanged between the captains from Trstenica and the Ragusa Senate between l577 and l665 (Doc. and Acts XVI, no 450 of the Archives):
…Captain B.Martinovich writes from Trstenica that on October 23, l570, a Venetian galley arrived on the island of Korchula with news of the battle of Lepanto on October 7 between the Turkish and Christian fleets.
…Captain Tomo Basiljevich writes from Trstenica that he received copies of the "pursuit" letter of March l2, l612, (one by sea and one by land) for himself, and for the captain on the island of Lastovo.He warned the local inhabitants to inform him about the fugitives.
…An October l6, l665 secret decision by the Senate orders the Trstenica captain V.Skopich to learn from D. Andjelkovich, the chaplain on Korchula, who from Dubrovnik is sending reports to the Venetian naval Commanders in Korchula.
Ambassadors were sent every two years to Istanbul with a tribute of l2,000 ducats. Their detailed orders, given orally and in writing, instruct them as follows: "In your travels or at the Court (in Istanbul), if something happens that you consider important, we order you to inform us, and not to spare horse couriers, for we shall pay them. Be cautious in sending them."
Ambassadors were to find and use "our" people; that is, court officials native to Bosnia, Serbia, and Croatia who spoke "our" language. One friendly to Ragusa was the grand vizier in the Sultan's court, Mehmed pasha Sokolovich.
In its instructions to ambassadors, the Senate lists the officials at the Istanbul court who must be given presents. In one, however, the Senate singles out one to whom nothing should be given, for he has reneged on his promise to help. Ragusa's Ambassadors, consuls, and government officials often used bribes. An old Ragusa dictum was, "Against those who threaten us with iron bullets, we use gold bullets ". Another was "Polite with everyone, sincere with no one".
I. Mitic (page l28 of his book): "In addition to her consuls and various special envoys, the Dubrovnik Republic used prominent natives to perform important services in the capitals in Europe. They informed systematically the Dubrovnik Senate about military, political, and other events and trends." Among the natives of Dubrovnik occupying important positions abroad was R. Boshkovich, who left Dubrovnik at age l5 to become a Jesuit in Rome and came back to Dubrovnik for only one short visit. The Senate began asking his help in l755, while he was still in Rome, and continued asking until his death.." Boshkovich became the de facto Dubrovnik ambassador in Paris, informing on events in France, including an assessment of the personality of the new king, Louis XVI. In his letter to the Senate (l781), Boshkovich includes an article from the "Gazette de Leyde" interesting to Dubrovnik businesses in Morocco. He regularly sent the "Courier de l'Europe". In the same letter, he speaks of the mismanagement of Dubrovnik businesses in Marseille, citing the incompetence of its consul there. In l781, Boshkovich wrote that he could no longer send letters to Dubrovnik, for he had been appointed chief of optics in the navy of France and was required to take French citizenship. In reply, the Senate of Dubrovnik sent Boskovich a special code to use in the future.
In the late 1500s, newspapers appeared first in Venice, then in other countries. The Ragusa government perceived their importance to intelligence and security. In the l8th century, the Senate received the following newspapers: "Gazetta di Toscan" from Livorno; "Notizie del Mondo" from Venice; and the "Gazette de Leyde" from Holland. And the Livorno Consul sent "Gazetta di Notizie" and the "Gazzeta delle Correnti Notizie."9
Uses of RISS
Ragusa used the information to solve specific political problems and to obtain the good will of the surrounding powers. The Archives also contain evidence of Ragusa's technological intelligence effort; for example, the appearance of artillery, shipbuilding, and information.about economic changes in the Mediterranean after the discovery of America.
The l602-5 Lastovo island rebellion and occupation by Venice illuminates the Ragusa Republic's use of diplomacy based on first-class intelligence. The inhabitants of Lastovo rebelled in l602 to defend their traditional rights; Venice then occupied the island..Well-informed of the attitude of the dominant Mediterranean powers concerning the Venetian occupation, Ragusa, applying diplomatic pressure, asked Venice to withdraw from Lastovo. As reported, the Sultan told the Venetian ambassador to Istanbul "If you don't ask Venice to retreat from Ragusa's territory, I'll have your head cut off" Venice left Lastovo in l605.10
To gain their protection, Ragusa routinely fed intelligence to all the surrounding powers, even in times of conflict and war. Evidence of this is the only study of Ragusan intelligence written in Croatian during the Communist regime. The Trstenica captains' messages were from Archive documents found by the Tito police. Historian V. Chaldarevich, who was close to the Communist Party of Bosnia, published in "Narodna Milicija" No 7-8, l958, a survey of Ragusa I&S, under the title: "Dubrovnik: the Center of Europe's Intelligence Service." The paper concentrated on Ragusa's use of intelligence to obtain the goodwill of its potential protectors .11
In order to have the exclusive use of intelligence, the Senate (an ordinance of Dec. 28, l526) forbade the sending of information about the Turks abroad; "Those found guilty, whether noble, plebeian, or priest, will be fined l00 gold ducats or sentenced to six months in prison." In addition to Chaldarevich's paper, researchers in the Archives of the Vatican, Istanbul, Madrid, and Vienna found evidence of Ragusa' s providing intelligence to the powers, as shown in the following table. (Two historians from Dubrovnik perceive the current importance of intelligence: Sundrica in l999, and Bilich in 2000. Other history students in Croatian universities, once aware of the current I&S revolution, will certainly study the rich Ragusa I&S tradition).
Ragusa Supplying Intelligence to its Protectors at War with each
other Austria, Turkey, Spain, Vatican
To Louis, the King of Austria, l6 May 1373
The Senate of Ragusa: "We the sworn servants of your majesty are bound by duty to inform you of everything we learn that the Venetians are doing against your lands".
To the Sultans of Turkey Bayazit II, 7 April 1495
Thanks Ragusa Senate for the information that his brother Dzem has died in Rome and requests further information.
Suleiman I, 31 December l530
"I have ordered that henceforth you shall not interrupt the flow of your information nor cease to find out from the troops of the dust like infidels from them what their absurd thoughts and guesses are."
To the Sultan, 11 November l570
"Twelve galleys of the Pope have united with 49 of the King of Spain and have passed Corfu to unite with the Venetian fleet at Candia, altogether l85 large galleys forming a league".
To Carl V of Spain12
From the Senate through A. Djurasevich, the Ambassador in Madrid, January 13, l545:
"We received a letter from our agents in Istanbul requesting our regular tribute, since the Sultan and his army are going to Persia. Tell the Emperor, 'We inform Your Majesty of this so that you know that we are always devoted to you'."
To the Vatican: l606-l660
Source: I. Duichev, "Avvisi di Ragusa", l935
12, January, l607: In Istanbul, the great Vizier Dervish-pasha has been killed and replaced by Nurach-pasha
23, May, l646: The Senate is informed of the sudden departure from Istanbul of 20 war ships and arrival of gunpowder and guns from Belgrade.
26, August, l648: The Sultan has lost the throne and his life; the new Sultan is Muhamed, son of the late Ibrahim.
RISS: Model for the 21st Century
"Do not laugh: it is I who anticipate the future and know its thought"
Our insights about the future can help us discover the past. I found a number of predictions by farsighted thinkers regarding our intelligence revolution. For example, in the l920s, Walter Lipmann, observing the proliferation of knowledge, foresaw the emergence of organized intelligence. J. Dewey offerred social intelligence as the alternative to laissez faire capitalism and totalitarianism. Theillard de Chardin also intuited the emergence of our intelligence era: observe, the ABB corporation advertising its "Brainpower"; the Warburg Bank its "Global Intelligence"; Microsoft its "Intelligent Information"; IBM its "Intelligence Program"; Stockholm city its "Municipal Intelligence Department", consultant Anderbjörk his "Community Intelligence Services"; Robert Steele his "Open Sources Public Intelligence".
Is Ragusa's I&S relevant in today's intelligence environment? More than six billion individuals who occupy as many social systems, towns, corporations, and organizations are following the Ragusa model; that is, adapting creatively to a fluid environment.
Our world will be based on an enlightened "New Deal" capitalist system. In l930s, when the U.S. suffered a depression, Franklin D. Roosevelt introduced the "New Deal" to improve the welfare of broad sections of the population, and to create the production for their needs. Today, the "new deal" will again emerge as a result of mass-production capitalism. Henry Ford introduced mass production capitalism in 1916, when he realized that his workers could not afford his automobiles. Mass production in former Communist and undeveloped countries will bring about a better life, one based on employment, good working conditions, education, health, and freedom.
Ragusa's use of I&S to remain free is a paradigm for social systems in our world beset by complex global problems. I hope that professional historians will inform the public of the unparalleled I&S experience of Ragusa/Dubrovnik.
Among the professionals who helped me at the Dubrovnik Archives, I thank especially Marijan Sivric, Milenko Foretic, Ivo Veselic, and the librarian, Maria Veselic.
1 Middle Ages Latin proverb: intelligence of making money.
2 Serafin Cerva, Dominican priest, in his history of Dubrovnik (1744) writes:"Venetorum regendi formamimitati sunt Ragusini"( "The form of government of Venice is imitated by the Ragusans").
3 I. Mitich, (in Croatian). Dubrovnik State in the International Community, 1988.
4 "Lettere di Ponente", ICC 81-89.
5 Venice's "Committee dei Dieci", its intelligence and security body, was formally established in 1340, according to Preto.
6 P.Preto published a paper , a dictionary of terms for the I&S personnel in Venice.
7 Published in Zagreb by the Yugoslav Academy of Science, 1893.
8 S. Dedijer,"British Intelligence-The Rainbow Enigma", Int. Jour.of Intell. & Counterintel."Vl, N 2, 1986.
9 see D.Zivojinovic, Amerieka Revolucija i Dubrovaeka Republika, 1763-1790.
10 I have been informed that in the Archives here, there are hundreds of documents on the Lastovo case. My source is the first chapter of Samardzich's book.
11 I was unable to find the article in Yugoslavia, but found it in the Library of Congress in Washington, and presented it to the Archives.
12 M.P.Bovich,"Entre la Cruz e la Media Luna, Ragusa intelligence to the court of the Republic of Spain about the Turks in the l6th Century" (in Croatian and Spanish), Zagreb 2000.
Anselmi, S. "Motivazioni econmiche della neutralita di Ragusa nell* Cinquecento", pp. 25-53, di Vittorio, A.
Beretic, I. (in Croatian). The Fortifications of Dubrovnik, 1975.
Biegeman, N.H. "Ragusa Spying for the Ottoman Empire". Diuynments, Belletin, XXVIII, Ankara, 1963.
Carter, F.W. Dubrovnik(Ragusa): A Classic City-State, 1975.
Chaldarevic, M.( in Croatian) "Middle Ages Dubrovnik: An Important Center of the Intelligence Service," Narodna Milicija, br.7.8, 1958.
Dedijer ,S. "Intelligence and Security-Much Past, Little History", lecture, Lund, 1985.
Duichev, I. Avvisi di Ragusa.Documenti sull'Impero Turco nel secolo XVII e sulla guerra di Candia, Rome, 1935.
Foretich,V (in Croatian). History of Dubrovnik to l808, I, II, Mat.Hrv., 1980.
Klarwill,von V. The Fugger News Letters. Second Series, London, 1926.
Markovich,V.(in Croatian). Rudjer Boskovich, vol. I.. Zagreb, 1952.
Mitich, I.(in Croatian). Consuls and the Consul Service of Old Dubrovnik. JAZU, 1973.
Mitich, I.(in Croatian). The State of Dubrovnik in the International Community: 1358-1815. JAZU, 1988.
Popovich,T.(in Serbian). Turkey and Dubrovnik in XVI Century. SAN, Belgrade, 1973.
Polich-Bobich,M.(in Croatian and Spanish). Entre dela Cruz y la Media Luna-Avisos de Ragusa a la Corte de Rey de Espana Sobre los Turos en el Siglo X. Zagreb, 2000.
Preto, P. "Lo spionaggio economico", ch. 10, and "Ragusa e Venezia:Guerra di ' Nove' e di Spie".
I Servizi Segreti di Venezia, Il Saggiatore, 1994.
Preto, P. "Le parole dello spionaggio". Lingua Nostra. December, 1996.
Samardzic, R.( in Serbian). The Great Dubrovnik Century. Belgrade, 1983.
Razzi, Serafino. La Storia di Ragusa, 1595.
Schiele, H.A. Ricker, M. "Nachrichtendienst" in Betriebswirtschaftliche Aufschusse aus der Fuggerzeit. Berlin, 1967.
Stipetich, V.Habek, M. Buzadzich. "Benedetto Cotruglii of Dubrovnik". Amsterdam: April, 1998.
Sundrica, Z.(in Croatian). "The Intelligence Service of the Dubrovnik Republic in l8th Century ( in relation to Austria)". Anali, JAZU, Dubrovnik, XXXVII, 1999.
Visconti, M. Grande Storia di Venezia. Demetra, 1999.
Vojnovich, L.( in Croatian). Dubrovnik and the Osman Empire. SAN, 1898.
Zivojinovich, D.(in Serbian). American Revolution and the Dubrovnik Republic, 1763-1790. Prosveta, 1974.