The Klis Fortress (; ) is a medieval fortress situated above the village of Klis, near Split, Croatia. From its origin as a small stronghold built by the ancient Illyrian tribe Dalmatae, to a role as royal castle and seat of many Croatian kings, to its final development as a large fortress during the Ottoman wars in Europe, Klis Fortress has guarded the frontier, being lost and re-conquered several times throughout its 2,000-year history. Due to its location on a pass that separates the mountains Mosor and Kozjak, the fortress served as a major source of defense in Dalmatia, especially against the Ottoman Empire. It has been a crossroad between the Mediterranean Sea and the Balkans.
Since Duke Mislav of the Duchy of Croatia made Klis Fortress the seat of his throne in the middle of the 9th century, the fortress served as the seat of many Croatia's rulers. His successor, Duke Trpimir I, is significant for spreading Christianity in the Duchy of Croatia. He expanded the Klis Fortress, and in , in the valley under the fortress, he built a church and the first Benedictine monastery in Croatia. During the reign of the first Croatian king, Tomislav, Klis and Biograd na Moru were his chief residences.
In March 1242 at Klis Fortress, Tatars serving in the Mongol army suffered a major defeat while in pursuit of the Hungarian army led by King Béla IV. During the Late Middle Ages, the fortress was governed by Croatian nobility, amongst whom Paul I Šubić of Bribir was the most significant. During his reign, the House of Šubić controlled most of modern-day Croatia and Bosnia. Excluding the brief possession by the forces of Bosnian King, Tvrtko I, the fortress remained in Hungaro-Croatian hands for the next several hundred years, until the 16th century.
Klis Fortress is best known for its role in the Ottoman invasion of Europe in the early 16th century. Croatian captain Petar Kružić led the defense of the fortress against a Turkish invasion and siege that lasted for more than a quarter of a century. During this defense, as Kružić and his soldiers fought without allies against the Turks, the military faction of Uskoks was formed, which later became famous as an elite Croatian militant sect. Ultimately, the defenders were defeated and the fortress fell to the Ottomans in 1537. After more than a century under Ottoman rule, in 1669, Klis Fortress was besieged and seized by the Republic of Venice. The Venetians restored and enlarged the fortress. In 1797, the fortress was taken by Austria after the Fall of the Republic of Venice. Today, Klis Fortress contains a museum where visitors to this historic military structure can see an array of arms, armor, and traditional uniforms.
Location The fortress is located above the village of Klis, from the Adriatic Sea, on a pass that separates the mountains Mosor and Kozjak, at the altitude of , northeast of Split in Croatia.Hrvatski leksikon (1996), p. 470. Owing to its strategic position, the fortress was one of the region's most important fortifications in its history.
Perched on an isolated rocky eminence, inaccessible on three sides, the fortress overlooks Split, the ancient Roman settlement of Salona, Solin, Kaštela and Trogir, and most of the central Dalmatian islands. Historically, the fortress has controlled access to and from Bosnia, Dalmatia and inland Croatia. The importance of such a position was felt by every army that invaded, or held possession of this part of Croatia. Klis Fortress was a point against which their attacks were always directed, and it has been remarkable for the many sieges it withstood. It has been of major strategic value in Croatia throughout history.
History
Ancient stronghold of Illyrians and Romans
The ancient Illyrian tribe of the Dalmatae, who held a stronghold on this spot, are the first known inhabitants to have lived on the site of today's Klis Fortress. They were defeated several times, and in the year 9 AD, finally annexed by Romans. Today's Klis Fortress was known to the Romans by the name of "Andetrium" or "Anderium",Royal Geographical Society (1856), p. 589. and in later times "Clausura", which is the origin of later "Clissa" and modern "Klis".Wilkinson (1848), pp. 169–172. To the Romans, Klis became famous for its celebrated siege by Augustus, at the time of the Illyrian revolt in Dalmatia.Collection (1805), pp. 111–116. The road that lead from Klis to Salona was called "Via Gabiniana" or "Via Gabinia", which according to an inscription found at Salona, appears to have been made by Tiberius. Southeast of the fortress, the traces of a Roman camp are still visible, as well as an inscription carved on a rock; both which are supposed to be contemporary with the siege under Tiberius. The description of this siege during the Illyrian Wars demonstrates that this place was strong and unreachable in those times.
Migration period and the arrival of the Croats
After the fall of the Roman Empire, Barbarians plundered the region around Klis.Fine (The early medieval Balkans – 1991), p. 22. First it was ruled by Odoacer, and then by the Theodoric the Great, after he eliminated Odoacer, and set up an Ostrogothic Kingdom. After Justinian I fought an almost continual war for forty years to recover the old Roman Empire, he seized Dalmatia, and Klis was from 537, a part of Byzantine Empire. The name of Klis (Kleisa or Kleisoura) was first described in chapter 29 of Emperor Constantine Porphyrogenitus' De Administrando Imperio.Curta (2006), pp. 100–101. While describing the Roman settlement of Salona, Constantine VII speaks of the stronghold, which may have been designed or improved, to prevent attacks on the coastal cities and roads by Slavs.
Salona, the capital of the province of Dalmatia was sacked and destroyed in 614 by Avars and Slavs.Fine (The early medieval Balkans – 1991), pp. 34–35. The population fled to Diocletian's walled palace of Split, which was able to resist the invaders. Thereafter, Split rose quickly in importance as one of Dalmatia's major cities. In the 7th century the Avars were driven out by a second wave of Croats, on the invitation of Emperor Heraclius, in order to counter the Avar threat to the Byzantine Empire.Constantine Porphyrogenitus, De Administrando Imperio, ed. Gy. Moravcsik, trans. R.J.H. Jenkins, rev. ed., Washington, Dumbarton Oaks Center for Byzantine Studies, 1967.
Royal Castle
From the early 7th century on, Klis was an important Croat stronghold, and later, one of the seats of many Croatia's rulers. In the 9th century, Croatian duke Mislav of the Duchy of Croatia, from 835 to 845, made the castle of Klis seat of his throne. Despite Frankish overlordship, the Franks had almost no role in Croatia in the period from the 820s through 840s. After Mislav's death, starting with Duke Trpimir I, Klis was ruled by royal members of the House of Trpimirović, who were at first Dukes of the Croatian Duchy (dux Croatorum), and afterwards Kings of the Croatian Kingdom (rex Croatorum). They developed the early Roman stronghold into their capital. Relations with the Byzantines greatly improved under the Croatian duke Trpimir I, who moved the dux's main residence from Nin to Klis.Fine (The early medieval Balkans – 1991), p. 257.
The reign of Mislav's successor Trpimir I, is significant for spreading Christianity in the medieval Croatian state, and for the first mention of the name "Croats" in domestic documents.Curta (2006), p. 139.Hrvatski leksikon (1996), p. 1022. On 4 March, in 852, Trpimir I issued a "Charter in Biaći" () in Latin, confirming Mislav's donations to the Archbishopric in Split. In this document Trpimir I named himself; "By the mercy of God, Duke of Croats" (), and his realm as the "Realm of the Croats" (). In the same document Trpimir I mentioned Klis as his property — seat. Under Klis, at , the duke Trpimir built a church and the first Benedictine monastery in Croatia, which is known from the discovery of a stone fragment on a gable arch from an altar screen, inscribed with the duke's name and title.
Archaeological excavations found that a church dedicated to Saint Vitus was founded in the 10th century by a certain Croatian king, along with his wife, Queen Domaslava, which got destroyed during Ottoman conquests in the 16th century.
A controversial Saxon theologian of the mid-9th century, Gottschalk of Orbais, spent some time at Trpimir's court between 846 and 848. His work "De Trina deitate" is an important source of information for Trpimir's reign. Gottschalk was a witness to the battle between Trpimir and Byzantine strategos, when Trpimir was victorious. During the reign of Croatian king Tomislav, who had no permanent capital, the castle of Klis along with Biograd, were his chief residences.Fine (The early medieval Balkans – 1991), p. 263.
Knights Templar
From the early 12th century, and after the decay of the native Croatian royal family of Trpimirović, the castle of Klis was mainly governed by Croatian nobility, under the supremacy of Hungarian kings. The Kingdom of Croatia and the Kingdom of Hungary were, from 1102, in a personal union of two kingdoms, united under the Hungarian king.The actual nature of the relationship is inexplicable in modern terms because it varied from time to time. (Bellamy (2003), p. 38.) Sometimes Croatia acted as an independent agent and at other times as a vassal of Hungary. (Bellamy (2003), p. 38.) However, Croatia retained a large degree of internal independence. (Bellamy (2003), p. 38.) The degree of Croatian autonomy fluctuated throughout the centuries as did its borders. (Singleton (1989), p. 29.)Regional Surveys of the World (1996), p. 271.
Andrew II of Hungary was extremely favorably disposed towards the Templars.Hunyadi and Laszlovszky (2001), p. 137. During his participation in the Fifth Crusade, he appointed Pontius de Cruce, Master of the Order in the Hungarian Kingdom, as a regent in Croatia and Dalmatia. After his return in 1219, in recognition of the great logistical and financial support which the Order had given him during the campaign, he granted the Order the estate of Gacka. Even before his departure from the city of Split in 1217, he had made over to the Templars the castle of Klis (Clissa), a strategic point in the hinterland of Split (Spalato), which controlled the approaches to the town. The king Andrew was reluctant to entrust the castle of Klis to any of the local magnates, knowing what great harm could come from that castle.Archdeacon (2006), pp. 161–163. It was the king's will that Split receive the castle of Klis for the defense of their city. The city of Split showed little interest in the royal favors, so the king entrusted Klis into Templars hands. Shortly after this, the Templars lost Klis, and, in exchange, the king gave them the coastal town of Šibenik (Sebenico).
Mongol siege
Tatars under the leadership of Kadan experienced a major failure in March 1242 at Klis Fortress, when they were hunting for Béla IV of Hungary. The Tatars believed that the king was in the Klis Fortress, and so they began to attack from all sides, launching arrows and hurling spears.Archdeacon (2006), p. 299. However, the natural defenses of the fortress gave protection, and the Tatars could cause only limited harm. They dismounted from their horses and began to creep up hand over hand to higher ground. But the fortress defenders hurled huge stones at them, and managed to kill a great number. This setback only made the Tatars more ferocious, and they came right up to the great walls and fought hand to hand. They looted the houses in the outskirt of the fortress and took away much plunder, but failed to take Klis altogether. Upon learning that the king was not there, they abandoned their attack, and ascending their mounts rode off in the direction of Trogir, a number of them turning off toward Split.