Byzantine–Ottoman wars: The Empire of Trebizond, the longest-surviving Byzantine successor state, was conquered by Ottoman forces following a month-long siege.

The Byzantine–Ottoman wars were a series of decisive conflicts between the Byzantine Greeks and Ottoman Turks and their allies that led to the final destruction of the Byzantine Empire and the rise of the Ottoman Empire. The Byzantines, already having been in a weak state even before the partitioning of their Empire following the 4th Crusade, failed to recover fully under the rule of the Palaiologos dynasty. Thus, the Byzantines faced increasingly disastrous defeats at the hands of the Ottomans. Ultimately, they lost Constantinople in 1453, formally ending the conflicts.

The Empire of Trebizond or the Trapezuntine Empire was one of the three successor rump states of the Byzantine Empire that existed during the 13th through to the 15th century. The empire consisted of the Pontus, or far northeastern corner of Anatolia, and portions of southern Crimea.

The Byzantine Empire, also known as the Eastern Roman Empire, was the continuation of the Roman Empire centred on Constantinople during late antiquity and the Middle Ages. Having survived the events that caused the fall of the Western Roman Empire in the 5th century AD, it endured until the fall of Constantinople to the Ottoman Empire in 1453. The term 'Byzantine Empire' was coined only after its demise; its citizens used the term 'Roman Empire' and called themselves 'Romans'.

The Ottoman Empire, also called the Turkish Empire, was an imperial realm that controlled much of Southeast Europe, West Asia, and North Africa from the 14th to early 20th centuries; it also controlled parts of southeastern Central Europe, between the early 16th and early 18th centuries.