Which treaty signed in 1590 ended the Ottoman–Safavid War and gave the Ottomans control of Azerbaijan and the Caucasus?

The Treaty of Constantinople (1590) ended the Ottoman–Safavid War of 1578–1590 and awarded the Ottomans extensive territories in Azerbaijan and the Caucasus.

Signed on 21 March 1590 in Constantinople, the treaty was also known as the Peace of Istanbul or the Treaty of Ferhad Pasha. Safavid Iran accepted highly unfavorable terms while Shah Abbas I consolidated power and dealt with threats elsewhere.

The settlement transferred most of the southern Caucasus, including Georgia, Shirvan, Karabakh, and the Erivan region, as well as Azerbaijan and Tabriz. It also recognized Ottoman control over territories in Mesopotamia, Kurdistan, and western Iran. A religious clause required the Safavids to stop cursing the first three caliphs.

A common mix-up is the Treaty of Amasya, which ended an earlier Ottoman–Safavid conflict in 1555. The 1590 treaty’s gains were temporary: Shah Abbas later rebuilt Safavid strength and recovered most of the lost territories in subsequent wars.