AUSTRO-OTTOMAN WARS. By the early sixteenth century, there was steady low-level conflict in a border zone roughly defined by the Danube and Sava rivers between the Ottomans and European Christian rulers as a result of the Ottoman conquests of Balkan territory that began in the late fourteenth century. In 1520, a new Ottoman sultan, Suleiman I (also called Suleiman the Magnificent), took the throne. After the Ottomans secured control over Egypt by defeating the Mamluks and established an eastern border by defeating the Safavids of Iran at Chaldiran in 1514, attention turned back to the Balkans. When Louis II, king of Hungary and Bohemia (ruled 1506–1526), rejected Suleiman's demand for tribute, the sultan seized Belgrade and marched north, inflicting a severe defeat on a Hungarian army at Mohács on 28 August 1526. Hungary had been weakened by conflicts between various domestic groups as well as by competition between its ruler and the Holy Roman emperor. The Ottoman army pulled back from the Danube only after conquering Buda in December 1526.
King Louis II drowned as he was fleeing from the advancing Ottomans, which caused a succession crisis between the Habsburg Ferdinand (who later became Emperor Ferdinand I and ruled 1558–1564) and the local Transylvanian ruler, János Szapolyai. Suleiman installed Szapolyai at Buda but conceded the western third of Hungary to Ferdinand. The sultan tried to augment his conquests in Europe over the next few years and first laid siege to Vienna in September–October 1529 but had to retreat because of a snowfall.
THE OTTOMAN-HABSBURG WAR (1593–1606)
By 1568, the Ottomans controlled Transylvania as an autonomous principality, leaving western Hungary to the Habsburgs. For the next two decades, the Austrian-Ottoman border was quiet, but Christian refugees from Ottoman territory were resettled on the Habsburg side of the "military frontier."
Hungary became divided into two parts: Royal Hungary, ruled by the Habsburgs, and Transylvania, ruled by the Ottomans. The Ottoman side of this border witnessed administrative instability and onerous, irregular financial demands made on the peasantry, but with considerable religious tolerance shown to various Christian sects. The Habsburgs maintained a more stable administration but showed little religious tolerance. This frontier experienced a continuous low-level Kleinkrieg: a "little war" of incursions and raids by both sides.
Resentment against Habsburg religious intolerance finally exploded into the Fifteen Years' War (1591–1606), into which the Ottoman forces were drawn. Despite Catholic-Protestant animosity, the Ottoman threat to Europe came to be viewed as more serious than Christian sectarian conflicts. In this time of heightened religious tension, several strategic frontier provinces revolted against Ottoman rule. After several encounters in which the Ottomans and the Habsburgs traded fortresses back and forth, a marginal Ottoman victory at Mezö-Keresztes finally halted a major Austrian offensive. When István Bocskay, the ruler of Transylvania, shifted loyalty back to the Ottomans in 1605, Austrian momentum was reduced. In the end, the Habsburgs signed two peace agreements in 1606. The first was the Peace of Vienna, in which the Habsburg emperor, Rudolf II, guaranteed the rights of Hungarian Protestants. The second was the Peace of Zsitvatorok (11 November 1606), in which the existing Austro-Ottoman borders were recognized, although the sultan agreed to forgo Transylvania's tribute payments.
Small border skirmishes then resumed while the Ottomans became embroiled in conflict with Iran, and the Habsburgs focused on European affairs. Competition for control of the Mediterranean between the Ottoman Empire and European powers erupted into a war between Venice and the Ottomans' North African corsairs in 1638. This was the first of many confrontations between the navies of the Ottomans, Venice, and militant religious orders like the Knights of St. John of Malta. Naval skirmishes near Crete and Malta, as well as Dalmatian land battles in the 1640s, set the stage for the Ottoman conquest of Crete in 1669.
THE WAR OF THE HOLY LEAGUE (1683–1699)
With growing fears of Ottoman expansion in the Mediterranean along with reduced tension in Europe after the 1648 Treaty of Westphalia, which ended the Thirty Years' War, Pope Alexander VII formed a Holy League in the 1660s to coordinate a new campaign against the Ottomans. Plans for a showdown between the Ottomans and this European coalition evolved over the next two decades. Two key battles, at St. Gotthard in 1664 and at Chotin in 1673, revealed substantial Ottoman military weaknesses. In the 1670s, an ambitious young Ottoman commander, Kara Mustafa Pasha, developed a plan to achieve fame by seizing Vienna, an objective that had eluded his army for many years.
Because of a new round of conflict within Europe, only the Polish king John Sobieski would commit forces to defend Vienna. The Ottomans advanced to Vienna and placed it under siege on 14 July 1683. As in 1529, they were at a disadvantage because they had failed to bring any heavy artillery—a deficiency that they tried unsuccessfully to overcome by mining Vienna's walls. Vienna's defenders mounted several effective attacks on them and as the siege wore on, Ottoman morale diminished. On 4 September, just as Vienna was finally beginning to weaken under the siege, the Ottomans failed to prevent the arrival of Sobieski's relief force.
The superior armament and tactics of the Polish army forced the besiegers to leave Vienna after only one day. Kara Mustafa Pasha was strangled in Belgrade on the sultan's orders as a result of this retreat as Austrian forces pushed deep into Hungary to take Buda in 1686. The Ottoman army then mutinied and deposed Sultan Mehmed IV, while the Venetians secured territory along the Adriatic and in the Morea (in the Peloponnese of modern Greece).
The new Sultan, Suleiman II, appointed the well-respected Fazil Mustafa as grand vizier in 1689, recapturing Belgrad and Niš. The deaths of both men in 1691 left no effective successors until Sultan Mustafa II took power in 1695. At the same time, other European powers were pressuring Austria to make peace with the Ottomans so that Austrian forces could unite with them against Louis XIV of France. Meanwhile, as many Ottoman areas in Europe fell into anarchy because of administrative and fiscal problems, Mustafa II campaigned to reconquer Hungary in 1697, where his defeat led to the 1699 Treaty of Carlowitz.
THE TREATY OF CARLOWITZ (1699)
In January 1699, the Ottomans, Austrians, and Venetians signed a treaty ending their conflicts based on the idea of uti possidetis —whoever controlled a territory at that time would keep it. This marked the first comprehensive peace treaty between the Ottoman Empire and European powers. The Ottomans relinquished Hungary and Transylvania to the Austrians; Dalmatia, the Morea, and some Ionian islands to Venice; and Podolia to Poland. This was the first written Ottoman acknowledgment of military defeat.
THE TREATY OF PASSAROWITZ (1718)
In conjunction with high Ottoman religious officials and the Orthodox patriarch of Constantinople (who had lost revenue from lands in the Morea because of the treaty of Carlowitz), Silahdar Ali Pasha, who had become grand vizier in 1713, started a war against the Venetians in 1715. When it appeared that the Ottomans threatened the Habsburgs in northern Dalmatia, Austria signed an alliance with Venice, which was then on the brink of financial collapse. In 1718, after numerous Austrian victories including Petrovaradin, the Ottomans, Austrians, and Venetians signed a treaty at Passarowitz. It gave the Banat of Temesvar, Lesser Walachia, northern Serbia, and northern Bosnia to Austria, but required Venice to return the Morea and Crete to the Ottomans, although Venice was allowed to keep its Ionian islands and the part of Dalmatia it had received at Carlowitz.
The Habsburg emperor Charles VI (ruled 1711–1740) agreed with the tsar in 1734 to cooperate secretly against the Ottomans. This agreement took effect when the Ottomans, encouraged by the French, declared war in May 1736 on both Austria and Russia to protest the placement of a pro-Russian candidate on the Polish throne. The Austrians tried to retake territory that they had given up at Passarowitz and captured Belgrade and Niš. Over the next two years, however, the Ottomans won a series of victories against them, leading them to sign the 1739 Treaty of Belgrade, which restored the border agreed upon at Carlowitz. The Russians, now deprived of the help of their Austrian allies, had to end their own hostilities with the Ottomans and soon signed a treaty that gave Azov back to the Ottomans.
AUSTRIA IN THE RUSSO-OTTOMAN WARS OF 1768–1774 AND 1787–1792
When a major war erupted between Russia and the Ottoman Empire in 1768 after a long period of peace, Austria at first stayed out of it because the Habsburgs did not want to encourage Russian expansion plans. After Russian success against the Ottomans, however, the Austrians entered the conflict in time to mediate the 1774 treaty of Küçük Kaynarca, but gained little new territory.
Austria was again prodded into action in 1787 by Russia, whose previous success fueled dreams of southward expansion. A series of decisive Russian and Austrian victories left these two powers in possession of much new territory and poised to advance toward Constantinople in the spring of 1790. However, the unfolding French Revolution caused other European powers to put pressure on them to end this war, which the Austrians did at Sistova in August 1791, several months before the Russian-Ottoman peace treaty. With European mediation, Austria agreed to give back its recent conquests in Bosnia and Serbia.
See also Austria ; Habsburg Dynasty: Austria ; Habsburg Territories ; Holy Leagues ; Hungary ; Ottoman Empire ; Passarowitz, Peace of (1718) ; Russia ; Russo-Ottoman Wars ; Suleiman I .
Cook, M. A. A History of the Ottoman Empire. Cambridge, U.K., and New York, 1976.
Goffman, Daniel. The Ottoman Empire and Early Modern Europe. Cambridge, U.K., and New York, 2002.
Shaw, Stanford J. History of the Ottoman Empire and Modern Turkey. Cambridge, U.K., and New York, 1976.