Byzantine–Ottoman Wars

Byzantine–Ottoman Wars
Clockwise from top-left: Walls of Constantinople, Ottoman Janissaries, Byzantine Flag, Ottoman Bronze Cannon.
Date 1265–1479 Location Asia Minor, Balkans Result Decisive Ottoman victory Fall of the Byzantine Empire
Belligerents
Byzantine Empire  Republic of Genoa  Republic of Venice Kingdom of Sicily Empire of Trebizond Despotate of the Morea Despotate of Epirus Principality of Theodoro Papal States	Ottoman Empire

The Byzantine–Ottoman Wars were a series of decisive conflicts between the Ottoman Turks and Byzantines that led to the final destruction of the Byzantine Empire and the rise of the Ottoman Empire.

In 1204 the Byzantine capital of Constantinople was sacked and occupied by the Fourth Crusaders, an important moment of the Christian East–West Schism. The Byzantine Empire, already weakened by misrule, was left divided and in chaos. Taking advantage of the situation, the Seljuk Sultanate of Rum began seizing territory in Western Asia Minor, until the Nicaean Empire was able to repulse the Seljuk Turks from the remaining territories still under Roman rule. Eventually Constantinople was re-taken from the Latin Empire in 1261 by the Nicaean Empire. However the position of the Byzantine Empire in the European continent remained uncertain due to the presence of the rival kingdoms of the Despotate of Epirus, Serbia and the Second Bulgarian Empire. This, combined with the reduced power of the Sultanate of Rum (Byzantium's chief rival in Asia) led to the removal of troops from Asia Minor to maintain Byzantium's grip on Thrace. However the weakening of the Sultanate of Rum was by no means a blessing to the Empire as nobles known as ghazis began setting up their fiefdoms, at the expense of the Byzantine Empire. While many Turkish beys participated in the conquest of Byzantine and Seljuk territory, the territories under the control of one such Bey named Osman I posed the greatest threat to Nicaea and to Constantinople.

...
Wikipedia