As the Rum Sultanate declined well into the 13th century, Anatolia was divided into a patchwork of independent Turkish principalities known as the Anatolian Beyliks. One of these beyliks, in the region of Bithynia on the frontier of the Byzantine Empire, was led by the Turkish tribal leader Osman I (d. 1323/4), a figure of obscure origins from whom the name Ottoman is derived.[34] Osman's early followers consisted both of Turkish tribal groups and Byzantine renegades, with many but not all converts to Islam.[35][36] Osman extended the control of his principality by conquering Byzantine towns along the Sakarya River. A Byzantine defeat at the Battle of Bapheus in 1302 contributed to Osman's rise as well. It is not well understood how the early Ottomans came to dominate their neighbors, due to the lack of sources surviving from this period. The Ghaza thesis popular during the twentieth century credited their success to their rallying of religious warriors to fight for them in the name of Islam, but it is no longer generally accepted. No other hypothesis has attracted broad acceptance.[37][38]
In the century after the death of Osman I, Ottoman rule had begun to extend over Anatolia and the Balkans. The earliest conflicts began during the Byzantine–Ottoman wars, waged in Anatolia in the late 13th century before entering Europe in the mid-14th century, followed by the Bulgarian–Ottoman wars and the Serbian–Ottoman wars waged beginning in the mid 14th century. Much of this period was characterised by Ottoman expansion into the Balkans. Osman's son, Orhan, captured the northwestern Anatolian city of Bursa in 1326, making it the new capital of the Ottoman state and supplanting Byzantine control in the region. The important port city of Thessaloniki was captured from the Venetians in 1387 and sacked. The Ottoman victory in Kosovo in 1389 effectively marked the end of Serbian power in the region, paving the way for Ottoman expansion into Europe.[39] The Battle of Nicopolis for the Bulgarian Tsardom of Vidin in 1396, widely regarded as the last large-scale crusade of the Middle Ages, failed to stop the advance of the victorious Ottoman Turks.[40]
As the Turks expanded into the Balkans, the conquest of Constantinople became a crucial objective. The Ottomans had already wrested control of nearly all former Byzantine lands surrounding the city, but the strong defense of Constantinople's strategic position on the Bosporus Strait made it difficult to conquer. In 1402, the Byzantines were temporarily relieved when the Turco-Mongol leader Timur, founder of the Timurid Empire, invaded Ottoman Anatolia from the east. In the Battle of Ankara in 1402, Timur defeated the Ottoman forces and took Sultan Bayezid I as a prisoner, throwing the empire into disorder. The ensuing civil war, also known as the Fetret Devri, lasted from 1402 to 1413 as Bayezid's sons fought over succession. It ended when Mehmed I emerged as the sultan and restored Ottoman power.[41]
The Balkan territories lost by the Ottomans after 1402, including Thessaloniki, Macedonia, and Kosovo, were later recovered by Murad II between the 1430s and 1450s. On 10 November 1444, Murad repelled the Crusade of Varna by defeating the Hungarian, Polish, and Wallachian armies under Władysław III of Poland (also King of Hungary) and John Hunyadi at the Battle of Varna, although Albanians under Skanderbeg continued to resist. Four years later, John Hunyadi prepared another army of Hungarian and Wallachian forces to attack the Turks, but was again defeated at the Second Battle of Kosovo in 1448.[42]
The son of Murad II, Mehmed the Conqueror, reorganized both state and military, and on 29 May 1453 conquered Constantinople, ending the Byzantine Empire. Mehmed allowed the Eastern Orthodox Church to maintain its autonomy and land in exchange for accepting Ottoman authority.[44] Due to tension between the states of western Europe and the later Byzantine Empire, the majority of the Orthodox population accepted Ottoman rule as preferable to Venetian rule.[44] Albanian resistance was a major obstacle to Ottoman expansion on the Italian peninsula.[45]
In the 15th and 16th centuries, the Ottoman Empire entered a period of expansion. The Empire prospered under the rule of a line of committed and effective Sultans. It also flourished economically due to its control of the major overland trade routes between Europe and Asia.[46][note 8]
Sultan Selim I (1512–1520) dramatically expanded the Empire's eastern and southern frontiers by defeating Shah Ismail of Safavid Iran, in the Battle of Chaldiran.[47] Selim I established Ottoman rule in Egypt by defeating and annexing the Mamluk Sultanate of Egypt and created a naval presence on the Red Sea. After this Ottoman expansion, competition began between the Portuguese Empire and the Ottoman Empire to become the dominant power in the region.[48]
Suleiman the Magnificent (1520–1566) captured Belgrade in 1521, conquered the southern and central parts of the Kingdom of Hungary as part of the Ottoman–Hungarian Wars,[49][50][failed verification] and, after his historic victory in the Battle of Mohács in 1526, he established Ottoman rule in the territory of present-day Hungary (except the western part) and other Central European territories. He then laid siege to Vienna in 1529, but failed to take the city.[51] In 1532, he made another attack on Vienna, but was repulsed in the Siege of Güns.[52][53] Transylvania, Wallachia and, intermittently, Moldavia, became tributary principalities of the Ottoman Empire. In the east, the Ottoman Turks took Baghdad from the Persians in 1535, gaining control of Mesopotamia and naval access to the Persian Gulf. In 1555, the Caucasus became officially partitioned for the first time between the Safavids and the Ottomans, a status quo that would remain until the end of the Russo-Turkish War (1768–1774). By this partitioning of the Caucasus as signed in the Peace of Amasya, Western Armenia, western Kurdistan, and Western Georgia (incl. western Samtskhe) fell into Ottoman hands,[54] while southern Dagestan, Eastern Armenia, Eastern Georgia, and Azerbaijan remained Persian.[55]
In 1539, a 60,000-strong Ottoman army besieged the Spanish garrison of Castelnuovo on the Adriatic coast; the successful siege cost the Ottomans 8,000 casualties,[56] but Venice agreed to terms in 1540, surrendering most of its empire in the Aegean and the Morea. France and the Ottoman Empire, united by mutual opposition to Habsburg rule, became strong allies. The French conquests of Nice (1543) and Corsica (1553) occurred as a joint venture between the forces of the French king Francis I and Suleiman, and were commanded by the Ottoman admirals Hayreddin Barbarossa and Dragut.[57] A month before the siege of Nice, France supported the Ottomans with an artillery unit during the 1543 Ottoman conquest of Esztergom in northern Hungary. After further advances by the Turks, the Habsburg ruler Ferdinand officially recognized Ottoman ascendancy in Hungary in 1547. Suleiman I died of natural causes in his tent during the Siege of Szigetvár in 1566.
Magnificent and his wife Hürrem Sultan, two portraits by 16th century Venetian painter Titian
By the end of Suleiman's reign, the Empire spanned approximately 877,888 sq mi (2,273,720 km2), extending over three continents.[58] In addition, the Empire became a dominant naval force, controlling much of the Mediterranean Sea.[59] By this time, the Ottoman Empire was a major part of the European political sphere. The Ottomans became involved in multi-continental religious wars when Spain and Portugal were united under the Iberian Union. The Ottomans were holders of the Caliph title, meaning they were the leaders of all Muslims worldwide. The Iberians were leaders of the Christian crusaders, and so the two were locked in a worldwide conflict. There were zones of operations in the Mediterranean Sea[60] and Indian Ocean,[61] where Iberians circumnavigated Africa to reach India and, on their way, wage war upon the Ottomans and their local Muslim allies. Likewise, the Iberians passed through newly-Christianized Latin America and had sent expeditions that traversed the Pacific in order to Christianize the formerly Muslim Philippines and use it as a base to further attack the Muslims in the Far East.[62] In this case, the Ottomans sent armies to aid its easternmost vassal and territory, the Sultanate of Aceh in Southeast Asia.[63][64] During the 1600s, the worldwide conflict between the Ottoman Caliphate and Iberian Union was a stalemate since both powers were at similar population, technology and economic levels. Nevertheless, the success of the Ottoman political and military establishment was compared to the Roman Empire, despite the difference in the size of their respective territories, by the likes of the contemporary Italian scholar Francesco Sansovino and the French political philosopher Jean Bodin.[65]
In the second half of the sixteenth century, the Ottoman Empire came under increasing strain from inflation and the rapidly rising costs of warfare that were impacting both Europe and the Middle East. These pressures led to a series of crises around the year 1600, placing great strain upon the Ottoman system of government.[66] The empire underwent a series of transformations of its political and military institutions in response to these challenges, enabling it to successfully adapt to the new conditions of the seventeenth century and remain powerful, both militarily and economically.[23][67] Historians of the mid-twentieth century once characterised this period as one of stagnation and decline, but this view is now rejected by the majority of academics.[23]
The discovery of new maritime trade routes by Western European states allowed them to avoid the Ottoman trade monopoly. The Portuguese discovery of the Cape of Good Hope in 1488 initiated a series of Ottoman-Portuguese naval wars in the Indian Ocean throughout the 16th century. Despite the growing European presence in the Indian Ocean, Ottoman trade with the east continued to flourish. Cairo, in particular, benefitted from the rise of Yemeni coffee as a popular consumer commodity. As coffeehouses appeared in cities and towns across the empire, Cairo developed into a major center for its trade, contributing to its continued prosperity throughout the seventeenth and much of the eighteenth century.[68]
Under Ivan IV (1533–1584), the Tsardom of Russia expanded into the Volga and Caspian region at the expense of the Tatar khanates. In 1571, the Crimean khan Devlet I Giray, commanded by the Ottomans, burned Moscow.[69] The next year, the invasion was repeated but repelled at the Battle of Molodi. The Ottoman Empire continued to invade Eastern Europe in a series of slave raids,[70] and remained a significant power in Eastern Europe until the end of the 17th century.[71]