The Ottoman Empire lasts about 600 years

Founded around 1299, the Ottoman state grew into a major power controlling parts of Europe, Asia and Africa. It was dissolved after World War I and the sultanate was abolished in 1922.

The 1299 founding date is traditional.

Context

The traditional start date of 1299 is linked to Osman I, leader of a Turkic frontier band in northwestern Anatolia. Little reliable written evidence survives from his time, and most narratives were composed generations later, so historians treat the date as a convention rather than a firm fact.

The state expanded into the Balkans in the fourteenth century, captured Constantinople in 1453, and under Selim I and Suleiman I took Syria, Egypt and much of the Arab world and parts of Hungary. At its height in the sixteenth and seventeenth centuries it controlled territory on three continents.

Defeat in World War I brought occupation and partition. The Turkish national movement under Mustafa Kemal abolished the sultanate on 1 November 1922, and the last sultan, Mehmed VI, left the country. The republic was proclaimed in 1923 and the caliphate was abolished in 1924. Counting from 1299 to 1922 gives about 620 years, so the usual figure of roughly 600 is approximate.

The Ottoman state therefore had a long life, though its borders, institutions and power changed greatly across the centuries.