The Ottomans in Medieval Eastern Europe

By Alice Isabella Sullivan

In the decades leading up to and after the fall of Constantinople on May 29, 1453, the Ottoman Empire was steadily making its way into Europe, turning first its attention toward points of resistance in the Balkan Peninsula and the Carpathian Mountain regions. The lofty aim was to reach eventually the gates of Rome, although it was never attained. The events of 1453 brought an end to the Byzantine Empire and ushered in a new era, viewed with suspicion and sometimes even terror among Europeans. The capital and center of Eastern Orthodoxy for well over a thousand years was no longer, and the Ottomans became a constant presence in Eastern Europe, gradually transforming daily life.

The Ottomans had certainly penetrated into the Balkans well before the fall of Constantinople, taking advantage of the weakened Byzantine state for territorial gain. Their first victory came in October 1352 when they defeated the Serbian armies at the Battle of Demotika. Two years later, at Gallipoli, the Ottomans established their first permanent settlement on European soil. In 1363, they captured Adrianople—a major Byzantine city in Thrace. Subsequently, Sultan Murad I (r. 1362–1389) renamed the city Edirne and established it as his capital. The prominent Balkan city served this function until the events of 1453 when the former Byzantine capital assumed this role. The incursions into the Balkans continued, and on September 26, 1371, the Ottomans invade Macedonia and defeated a Serbian army at Chernomen on the Maritza River, west of Edirne/Adrianople. This victory marked the beginning of the Turkish dominance over the southern Slavs.

The Ottoman advance into the Balkans after the Battle of Chenomen in 1371. Source:

In the last decades of the fourteenth century, as dynastic struggles further weakened the Byzantine Empire, the Ottomans secured additional territories in the Balkans and reached the banks of the Danube River. Following the Battle of Kosovo in 1389, Serbia came under partial Ottoman suzerainty, being required to pay an annual tribute and provide military assistance to the Porte if requested to do so. In such instances, the tributary states retained certain freedoms, such as the acknowledgment of the frontiers of the domain, the continued authority of the local rulers, the retention of former laws and customs, liberties in action in foreign affairs, and respect toward the Orthodox faith and the celebration of its rituals. As such, the lands under Ottoman control became “the friend of the [Porte’s] friends and the enemy of [the Porte’s] enemies.” Yet what seemed reasonable and even favorable in theory, did not always translate well into practice. Few were the local rulers who accepted Ottoman suzerainty for prolonged periods of time. Conflicts followed soon after such deals either as a result of the interruption of the tributary payment, local uprisings, or other political, economic, or military decisions from which conflict ensued.

By July 1393, the Ottomans had captured Tarnovo, ushering in the end to the Second Bulgarian Empire. The following year, they made their first incursions into the north-Danubian Romanian principality of Wallachia, extending to the south of the Carpathian Mountains. But it was not until 1420 that the Ottomans attacked one of the other Romanian principalities, Moldavia, located to the east of the Carpathians. They sought to capture its eastern strategic outpost: the fortress at Cetatea Albă on the Black Sea. But the Ottomans met strong opposition there from Moldavia’s Prince Alexander I (r. 1400–1432) and his armies, and were forced eventually to retreat from their campaign.

By 1396, the leaders of western and central Europe have had enough. With support from French crusaders, the Hungarian King Sigismund of Luxemburg (r. 1387–1437) organized an attack against the Ottomans. The encounter took place at Nicopolis where Sultan Bayezid I (r. 1389–1402) and his armies emerged victorious. Another Christian offensive made up of Serbian, Hungarian, and Polish forces encountered the Ottomans at Varna in 1444, but faced a defeat at the hands of Sultan Murad II (r. 1421–1444; 1446–1451) and his men. Sultan Murad II’s ambitions led to the sieges of Constantinople and Salonika in 1422, but both efforts ended in setbacks for the Turkish leader.


The conflict intensified after the fall of Constantinople in 1453. Moravian Serbia became officially a pashalic in 1459, after the capture of its last capital, Smederevo. The following year, the Despotate of the Morea (Peloponnesus) was captured, and completely wiped off the map in 1463. The same year, Bosnia, despite its protective ring of over 70 active fortresses, was conquered within just eight days. From that point onward, the Ottoman pressure on the Danube River and their presence in the Carpathian regions considerably increased. By 1462, the Ottoman armies had crossed the famed river and were engaging in extensive campaigns against the Wallachians; by 1470 they were fighting regularly against the Moldavians. The Ottomans regarded the inhabitants of these regions as “infidels” or “enemy infidels”, and their lands came to be part of the so-called house of war. But unlike the south-Danubian regions, the Carpathian territories never became a pashalic.

Albania offered the strongest resistance against the Ottomans, especially under the leadership of George Castriot, better known as Skanderbeg (r. 1443–1468). Following several failed campaigns in 1457, 1458, and 1462, his lands finally came under Ottoman control in 1466. Then, in 1482, after the fall of Novi, Herzegovina was conquered. The Ottoman Empire was, thus, swiftly making its way through the regions of southeastern Europe and successfully taking them, reaching the gates of Belgrade by 1521. In August of that year Belgrade was seized and the path opened to Hungary and Austria.

During the first decades of the sixteenth century, the Ottoman Empire continued its great military success and expansion. Under Sultan Selim I (r. 1512–1520), the Ottomans defeated the Mamluks in Egypt and annexed Cilicia, Syria, Jerusalem, and Egypt. His successor, Sultan Suleiman I “the Magnificent” (r. 1520–1566) continued the growth of the empire both east and west, seizing in the east the areas of historic Armenia, from Bitlis to Baghdad and Tabriz, and leading victorious campaigns in Eastern Europe.


Following the Battle of Móhacs on August 29, 1526, Hungary succumbed to the Turkish forces. Three years later, the Ottomans arrived before the walls of Vienna. Their subsequent siege of the Habsburg capital in 1529 turned out to be unsuccessful, however, and on October 15th of that year they blew the retreat. This military disaster showed that the Ottomans were vulnerable after all. What is more, it kindled in many Christian leaders and their subjects a certain hope that perhaps the successful westward advances of the Ottoman Empire could be halted after all.

Alice Isabella Sullivan is an art historian specializing in the medieval history, art, and culture of Eastern Europe and the Byzantine-Slavic cultural spheres. She has authored award-winning publications and is co-founder of North of Byzantium.

Click here to read more of Alice’s articles on Eastern Europe in the Middle Ages


Further Reading:

F. Babinger, Mehmed the Conqueror and His Time (Princeton University Press, 1992).

J. V. A. Fine, The Late Medieval Balkans: A Critical Survey from the Late Twelfth Century to the Ottoman Conquest (University of Michigan Press, 1994).

L. Pilat and O. Cristea, The Ottoman Threat and Crusading on the Eastern Border of Christendom during the 15th Century (Brill, 2017).

A. Pippidi, Byzantins, Ottomans, Roumains. Le Sud-Est européen entre l’héritage impérial et les influences occidentales (Honoré Champion, 2006).

J. O. Schmitt, The Ottoman Conquest of the Balkans: Interpretations and Research Debates (Verlag der Osterreichischen Akademie der Wissenschaften, 2016).


V. Stanković, ed., The Balkans and the Byzantine World Before and After the Captures of Constantinople, 1204 and 1453 (Lexington Books, 2016).


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