Emperor Friedrich in the Balkans (1189-1190). War de Jure and (or) War de Facto

Emperor Friedrich in the Balkans (1189-1190). War de Jure and (or) War de Facto
Emperor Friedrich in the Balkans (1189-1190). War de Jure and (or) War de Facto

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Contribution selected by Filodiritto among those published in the Proceedings “Southeast Europe: Hystory, Culture, Politics and Economy 2018”

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IVANOV Ivelin[1]


[1] “St Cyril and St Methodius” University (BULGARIA)

Email: i.ivanov@uni-vt.bg



The Third Crusade is generally well-studied and there exist a number of monographs, papers and other publications on its diplomatic and military history. Despite, the matters concerning the military clashes on the Balkans from the second half of 1189 and the beginning of 1190 are still underexplored. The paper focuses on some aspects of the Third Crusade (1189-1191) that are not a detailed study in historiography on the topic.

Traditionally, the historians show interest rather in King Richard’s and the King Philip’s actions, while the emperor Friedrich’s I campaign in the Balkans, and his dramatic and complicated relationships with the Byzantine emperor Issac II Angelos remains in the background.

The author analyses the march of the Crusaders from a different point of view, i.e. through an analysis of the evidence and facts about war de jure and war de facto during the campaign in the Balkans from 1189-1190.

Keywords: Third Crusade, Emperor Friedrich I, Byzantine Empire, medieval warfare, war de jure, war de facto

The research is based on information from Historia de expeditione Friderici imperatoris[1], Historia peregrinorum[2], Chronicon Magni Presbyteri[3], Arnoldi Lubecensis chronic[4], Gisleberti Chronicon hanoniense[5] and Historia of Nicetas Choniatis[6]. Paying my respect to the historiography on the topic, I would summarize two general conceptions on source data and the topic concerned. The first method of approach analyses the sources in an uncritical manner, accepting a position that the military conflict was provoked by the Byzantines (by reasons of the arrest of the German envoys in Constantinople, and the treaty between Issac II and Saladin from the end of 1189). Quite the contrary, other historians maintain a position that there exist both basic and secondary evidences for a Friedrich’s plan for a war against the Byzantine Empire before passing the Byzantine borders. Was there a such a plan and when (and where) the factual state of war between Friedrich and Issac developed into war de jure? This paper makes an attempt to give answers to this question.


The Friedrich’s Army: Strength, Organization and Armament

It is widely accepted that collecting the finances is a general task for the organization of every military campaign, but there is scanty information concerning the Friedrich’s crusade from 1189 in the written sources. In a letter from the end of August 1189, the German emperor demanded a tax-collection, as well as a deposit of this fund in the bank of Bernard of Venice[7]. As for the army strength and organization, the sources reveal various and quite controversial data. According to Gislebert, the army counted 100.000 warriors in its start in Regensburg on 11 May 1189[8]. Similarly, Albert of Bezano evidences that Friedrich leaded a 90.000 army at the moment he crossed the Hungarian border[9]. According to another chronicler – Arnold of Lubeck, the German crusaders counted 5000 knights and 100.000 infantry while was running across river Sava[10]. According to other authors, the army numbered 20.000 knights, not including the squires. Evidently, it is hard to reach the trough about the strength of the Crusaders without an additional information and analysis.

The author of Historia de expeditione Friderici imperatoris notes the most notable of the leaders in the army: 42 counts and bishops, 2 dukes and 24 noblemen[11]. Additionally, the chronicler notices “the rest of the crack troops from the emperor’s detachment”, as well as the Bohemians and the Hungarians. If we assume that every one of these 42 noblemen were a leader of between 40 and 60 knights (the reason for such a hypothesis is that many sources from the 12th-13th  cc. indicates that so called batallia numbered 40 to 60 knights), and that “the rest of the crack troops” was not less than 300 knights, we could count between 2000 and 2800 knights. Adding the rest of the troops (200-300 knights, the crossbowmen, the sergeants, about 200 Bohemians and not more than 300-400 Hungarians) we could assume that the Friedrich’s army counted about 6000 knights and other mounted men. Most probably, the strength of the army was between 18.000 and 20.000 men, and certainly, it was a well-organized and powerful force. Additionally, another evidence in support of the supposed number of the army there exists. It testifies that the army was accommodated in the half of the town of Philippopolis, which was totally evacuated by his inhabitants before the crusaders’ arrival[12].

Further, the sources note that the Bohemians and the Hungarians formed a vanguard, which task was to find out the way and to destroy all the barriers on the road. Also, this vanguard had to find a good place for a camping and to arrange it in a proper manner for the rest of the army which was approaching from the rear. The author of Historia de expeditione Friderici imperatoris records that “the Hungarian crusaders, who was known with the route very well, marched two or three days ahead of the army”[13]. According to Historia Peregrinorum, the duke of Swabia sent forward as a vanguard 500 heavily armed knights (their horses were all clad in steel) before getting through the Ichtiman pass in the Balkan mountain[14].

The analysis of the information about the organization and the marching order of Friedrich’s army leads to the following conclusions. Firstly, the crusader army follows the traditions of the Carolingian military system dating back in the 9th c., i.e. the emperor mobilized his secular and ecclesiastical vassals. According to the sources, the army was divided in four parts: a vanguard, two following contingents and a rear-guard leaded by Emperor Friedrich himself. This way, the most mobile and probably the best equipped and effective detachments were arranged at the front and at the rear of the long military column.

The sources also point out that the emperor Friedrich nominated one officer for every 50 knights (again very similar to the batallia of 40-60 men), as well as 60 noblemen who constituted both a military council and a military court[15]. No doubt, all of the organizational reforms were put into practice under stress of new circumstances, which arose after crossing the Byzantine border.

Contrariwise, the sources present scanty information about the armament of the crusaders in 1189-1190. The only considerable data from the chronicles describes squires and crossbowmen (actually crossbows). Slingers, who operated against the so-called bandits in the Silva Bulgarica (the Bulgarian forest) are also noted in a Friedrich’s letter addressed to his son Heinrich in August 1189[16].


The Byzantine Troops

Similarly, the sources are quite laconic in the descriptions of the Byzantine military, which opposed to the Friedrich’s crusaders in 1189-1190. According to Historia peregrinorum, Greeks, Wallachs, Bulgarians and some numerous allies (i.e. mercenary troops) began to fight against the crusaders by the order of the emperor just after the Germans encroached upon Byzantines territories[17]. The same Historia describes also Alans, who joined battles as Byzantine mercenaries and fought bravely and fiercely against the crusaders. Besides, the author of Historia peregrinorum testifies about multiple skirmishes with Cuman’s mounted troops[18]. The analysis of this and some other data leads to a conclusion that the mass of the mounted Byzantine troops was recruited from heavily armed Alans and light Cuman’s cavalrymen. Also, Expeditio Friderici describes multiple attacks from half-barbarians (Greeks, Bulgarians, Serbs and Vallachs), who made ambushes and shot with their bows on the rear-guard of the crusades in the so-called Silva Bulgarica[19]. It is quite complicated to reply the question who had actually been these bandits who ambushed the most vulnerable detachments in the German army because the information is too scanty. Most probably, they formed small bands on ethnical origin, and acted by the order of the Byzantine emperor or with his implicit consent. Evidently, the crusaders treated him as bandits and robbers, but not as captives, killing and hanging them on the roadside trees. The reason for such a treatment was that the crusaders de facto were still at peace with the Byzantines at that time, and every attacker on the Germans was regarded and treated as a bandit.

According   to   Nicetas   Honiatis, the Byzantine troops were organized in several detachments: the prōtostratōr (πρωτοστράτωρ) Manuel and the domestikos (δομέστικος) of the West-Alexios, were in charge of following the crusaders and ambush them at every possibility[20]. Also, the author of Expeditio Friderici notes that a part of the Byzantine army was under the command of the sebast (σεβαστ) Issac and fought against Serbian jupans[21].

According to another chronicle, the Byzantine emperor forwarded three armies against the crusaders, not giving any detailed information about their leaders and their strength[22]. The analysis of all the information leads to a conclusion, that there were three Byzantine armies, which operated in the Balkan lands of the Empire in 1189-1190. The most western of these armies (under the command of the sebast Issac) operated against the Serbs, while other two armies followed the crusaders at a close distance, attacked them sporadically, and did not allow the Germans to supply with food or to widen the territories under control. Besides, that conclusion puts many questions concerning the strategy and the tactics of the two sides in this strange war.


Battles and (or) Skirmishes? Ramparts, Fortresses and Sieges

Some of the researchers maintain an opinion, that the first key battle took place in the Ichtiman pass, but others bring such a statement in question. In reality, both Latin’s and Greek’s sources depicts much more crusaders’ than Greeks’ victories in this clash, which leads to a conclusion about a German military superiority in the concerned events. Such a thesis could reveal the grounds of the Byzantine strategy: avoiding decisive battles, striking the enemy by surprise, and disturbing the crusader’s communications and supply.

Additionally, the ramparts made of earth and wood and the solid castles and fortresses played an important role in this strategy.

Presbyter Magnus is among the chroniclers who describes the ramparts, which were built by the Byzantines in the passes and defiles not far off the town of Naissus. According to Historia peregrinorum, the Bohemians and the Hungarians moved one or two days ahead of the main army and destroyed by axes and fire the barriers on the road[23]. Also, the same author writes about a rampart constructed by stone walls and a wooden palisade in a valley on the road. Nicetas Choniates also confirms this information. He notes that the Greeks built many barriers from stone and wood in the passes, but they were useless against the approaching crusaders[24]. And here a question appeared: What exactly was a real purpose of the described ramparts and fortifications?

In my opinion, they were not constructed for a decisive resistance against the approaching Friedrich’s army, but only with a strategic purpose – to slow down the crusader’s advance and to not allow them to reach to the Straits and to Constantinople before the winter of 1189-1190.

However, the course of the future events demonstrated the usefulness of this strategy.

The control over the towns and the key fortresses was another aspect of the military conflict between the crusaders and the Byzantines. According to Expeditio Friderici I, the fortresses Veroes, Skribention, Brandevei and Pernis had been captured by assault, but not after a siege. Some other sources (for example Historia peregrinorum) give account of sieges.

According to the author, the Swabian duke took the fortress of Dimothika in Eastern Thrace by surprise and the Crusaders slaughtered 1500 Greeks, Turks and Allans. Similarly, the fortress of Manuak at the foot of the Rhodope Mountains were captured by assault, and according to the chronicler, there had been slaughtered 4000 Cumans and Greeks (quite obviously a highly exaggerated number). Additionally, Expeditio Friderici notes that a detachment led by the bishop of Wurzburg and three other counts seized two deserted towns and captured a third by force[25]. The analysis of this data shows in a clear manner that the most of the fortresses had been taken by surprise and assault, but not after a prolonged siege.


The Casualties

It is both quite interesting and very difficult to estimate the number of casualties in the medieval wars because of the scanty information on the one hand, and the exaggeration of the numbers from the medieval authors on the other. Arnold from Lubeck testifies that the locals from the region around the town of Sirmium killed with poisoned arrows 500 pedites (foot soldiers from non-aristocratic origin) who supplied the army from the country[26]. According to the author of Expeditio Friderici, the Patavian bishop and the Meranian duke killed 40 and hanged 24 captured bandits, i.e. totally 64 victims in a small clash[27]. Other information concerning the casualties could be extracted from the before mentioned letter of emperor Friedrich to his son Heinrich from the end of August 1189. There 100 dead from a natural cause and a great number of dead horses (most probably because of the lack of supplies and the attacks) is reported[28].

Also, Expeditio Friderici describes a great number of crusaders who were wounded by arrows and spears as a result of the assault against the fortress of Dimotika, but only 3 dead knights. It is hard to say whether the number of the casualties between knights was exactly noted, but it may safely be said that the number of casualties among the common soldiers was much more numerous. The same source testifies, that the Latins lost 14 people in an ambush close to the fortress of Batkun, and that there had been killed more than 300 Greeks in a following battle. In addition, Expeditio Friderici reports of 6 killed Cumans and 6 dead Cuman’s horses in a sudden clash between 17 mounted knights and 300 Cumans[29].

The analysis of the concerned information doesn’t lead to the final conclusions of the proportion of casualties to all army strength. But comparing the casualties in classes, battles and in the assaults of fortresses with the casualties from other causes of death (not in military actions), we could assume that the first outnumber the second.

The Strange War

But let us focus on the basic problem this paper puts just at the beginning: the war between crusaders and the Byzantines de facto and de jure. Who actually provoked the military conflict de facto, why and when this conflict grew into a war de jure? In fact, the Latin sources account emotional, but not reasonable (political) motives for the outbreak of this war.

According to the chroniclers, after receiving a confirmation of the sad news that his messengers to the Byzantine emperor had been imprisoned “the crusaders started to plunder the Greek’s properties and to destroy all the rest freely and without limitations”[30]. The most of the Latin writers justified the emperor Friedrich explaining his willingness to keep the peace, but the facts evidence against such a position. What Friedrich actually did after entering the Balkans in the summer of 1189 and why?

Actually, the sources note that the German emperor welcomed the Bulgarian messengers in Naissus in July 1189, and soon after that, he helped in contracting a marriage agreement between the Dalmatian duke Perthold and the Serbian jupan Stefan. Both these political acts were de facto directed to the Byzantine Empire and contradicted the German-Byzantine peace treaty from the previous year. But which were the real reasons for this act of hostility? According to Expeditio Friderici, Friedrich sent a new delegation to Constantinople demanding an immediate release of the German messengers in October 1189[31].

The Byzantine emperor indeed set the Germans free, but the Latins did not agree to compensate the Empire for all damages caused by the crusaders. Another Latin source – Historia Peregrinorum, describes that the emperor Issac II addressed new terms of an agreement to Friedrich on 28 October 1189.

According to the chronicler, emperor Issac II demanded noble hostages (the duke of Swabia and other six bishops in Friedrich’s will) in return for a free crossing of the Straits, markets with goods and money exchange for the crusaders, but the Byzantine initiative was turned down. Most probably, this refusal had been caused by a several reasons: 1) the crusader’s aversion to restoring or compensating the caused damages, 2) the Friedrich’s reluctance to hand back formal Byzantine territories in the East (as a result of a successful crusade), 3) or a clear plan for a war de jure against the Byzantine empire. The last could be also verified by another source: a letter from Friedrich to his son Heinrich with instructions for gathering finances, a fleet, and the Pope’s support for a war against Issac II[32]. At the same time, we couldn’t keep silent about the fact that emperor Isaac made a treaty with

Saladin at the end of the same year, i.e. after the concerned proposal to Friedrich from 28 October and the following German’s refusal. The reaction of the Hungarian king Bella III, who called back the most of his troops in November 1189, is also quite indicative of the Friedrich’s course of war de jure against the Byzantines. In my view, all the before mentioned testifies to a Friedrich’s plan for a war de jure against the Byzantine Empire from the beginning of November 1189. Finally, it is also worth to point out a brief note from the chronicler Albert from Bezano, that Friedrich planned to attack Constantinople[33].

Contrariwise, the Byzantine emperor avoided a direct and general military conflict or a war de jure. Actually, Isaac II realized that the Nurmberg’s treaty with Friedrich of 1088 gave the Byzantines a certain advantage. According to Ansbert and Historia Peregrinorum, after the negotiations went wrong, the emperor Friedrich and his barons invalidated the peace treaty, and declared a war on Byzantine Empire[34]. The sources give no information about all the Byzantine’s conditions, which were turned down by the crusaders, but it is obvious that it was only some casus belli for a war.

On the one hand, the declaration of war allowed the Germans to plunder freely, let us say on legal grounds, but on the other hand, the Crusaders became aggressors in Christian territories. This war de jure continued a short time (about two months, practically during the coldest winter months), and a new peace treaty with 14 clauses was signed on 24 February. What were the reasons for this outcome of the clash?

According to some sources, the emperor Friedrich was unpleasantly surprised to see only one Venetian ship and Genovese’s messengers who promised a military support (but in the future) at the Gallipoli peninsula shore on 21 March 1190. No doubt, Friedrich could rely also on Bulgarian and Serbian military support, but he and his barons also realized that it was possible, but useless to fight against the Byzantine Empire and to besiege Constantinople without a fleet.

Most probably, the German emperor was clear about a failure of the plan for an attack on the Byzantine capital before the arrival of the Byzantine envoys in the end of February 1190, but the final decision for a new peace treaty was made after the disappointment in his Italian allies on 21 March. All the concerned circumstances turned the war against Emperor Isaac in the useless and hazardous campaign.

In conclusion, I would point out that the two sides were in a war de facto all the time of the Friedrich’s campaign in the Balkans, but the war de jure continued only two months – January and February 1190. In final words, this war de jure was much more beneficial for Friedrich, than to Isaac. Firstly, it helped the Crusaders to keep the collected booty, and secondly, it led to an important diplomatic victory over the Byzantines. It concerned the Byzantine legacy, i.e. the former Byzantine territories, which were lost in the 11th c. Actually, the Byzantine emperor Isaac II did not successes to come to an agreement with the emperor Friedrich I for a future return of the ex-Byzantine territories in the East.

[1] Historia de expeditione Friderici imperatoris. (1965). Latinski izvori za balgarskata istoriya (LIBI), T. III, Sofiya, s. 245-291.; Historia de expeditione Friderici imperatoris (1928). Monumenta Germaniae Historica, SS, Nova series, vol. V, Berlin, pр. 15-70.

[2] Historia peregrinorum. (1965). Latinski izvori za balgarskata istoriya, T. III, Sofiya, s.  221 -244.; Historia peregrinorum (1928). Monumenta Germaniae Historica, SS, Nova series, vol. V, Berlin, pр.129-152.

[3] Chronicon Magni Presbyteri. (1965). Latinski izvori za balgarskata istoriya, T. III, Sofiya, 1965, s. 208-213.; Chronicon Magni presbyteri (1861). Monumenta Germaniae Historica, SS, vol. XVII, Hanover, pp. 476-534.

[4] Arnoldi Lubecensis chronica. (1869). Monumenta Germaniae Historica, SS, vol. XXI, pp. 100-250.

[5] Gisleberti Chronicon hanoniense. (1965). Latinski izvori za balgarskata istoriya, T. III, Sofiya, pp. 295-296.

[6] Nicetae Choniatae. Historia. (1983). Gratski izvori za balgarskata istoriya, T. XI, Sofiya (in Bulgarian), pp. 8-93.

[7] Historia de expeditione Friderici imperatoris. (1965), p. 265.

[8] Gisleberti Chronicon hanoniense. (1965), p. 296.; Hugonis Chronici Continuatio Weingartensis. (1869). Monumenta Germaniae Historica, SS, vol. XXI, Hanover, p. 476.

[9] Lazarov, Iv., P. Lungarova. (1993). Hronikata na Albert ot Bezano za Tretiya i Chetvartiya krastonosen pohod i preminavaneto im prez balgarskite zemi. – V: Studia protobulgarica et madiaevalia europensia. V chest na profesor Veselin Beshevliev. Veliko Tarnovo (in Bulgarian), p. 106.

[10] Arnoldi Lubecensis chronica. (1869), pp. 130-131. “Post hec vene runt ad fluvium qui Sowa dicitur, ubi imiltitudo exercitus dinumerata est, et inventa sunt quinquaginta milia militum et centum milia armatorum a bella vaientium”.

[11] Historia de expeditione Friderici imperatoris. (1965), pp. 248-249.

[12] Ibid., s. 263. If we assume that Plovdiv had at least 25,000-30,000 inhabitants at that time, that means about 8,000-10,000 houses, i.e. 4,000-5,000 homes occupied or 15,000-20,000 army.

[13] Ibid., p. 252.

[14] Historia peregrinorum. (1965), p. 231.

[15] Historia de expeditione Friderici imperatoris. (1965), p. 268.

[16] Georgiev, Sv. (1931–1932). Dve pisma na vidni krastonostsi ot Plovdiv prez 1189 g. – Izvestiya na balgarskoto istorichesko druzhestvo, XI-XII (in Bulgarian), p. 259.

[17] Historia peregrinorum. (1965), p. 224.

[18] Ibid., p. 238.

[19] Historia de expeditione Friderici imperatoris. (1965), p. 253.

[20] Nicetae Choniatae. Historia. (1983), p. 38.

[21] Historia de expeditione Friderici imperatoris. (1965), p. 257.

[22] Lazarov, Iv., P. Lungarova. (1993), p. 106.

[23] Historia peregrinorum. (1965), p. 225.

[24] Nicetae Choniatae. Historia. (1983), p. 39.

[25] Historia de expeditione Friderici imperatoris. (1965), p. 284.

[26] Arnoldi Lubecensis chronica. (1869), p. 171.

[27] Historia de expeditione Friderici imperatoris. (1965), p. 259.

[28] Ibid., p. 266.

[29] Ibid., pp. 276-277.

[30] Ibid., pp. 262-263.

[31] Ibid., pp. 270-272.

[32] Georgiev, Sv. (1931–1932). Dve pisma na (in Bulgarian), p. 261.

[33] Lazarov, Iv., Lungarova, P. (1993) (in Bulgarian), p. 107. The same opinion is expressed by Ani Dancheva-Vassileva, who believes that the German emperor had a plan to conquer Constantinople at the very beginning of the campaign. – See Dancheva-Vasileva, A. (1997). Tretiyat krastonosen pohod v Trakiya i sadbata na Plovdiv prez 1189-1190 g. (in Bulgarian). – Rodina, 1-2, pp. 58-63).

[34] Historia de expeditione Friderici imperatoris. (1965), p. 279.