In the winter of 1488, the Ak Koyunlu Turkomans led by Halil Bey attacked Georgia’s capital Tbilisi, and took the city after a long-lasted siege in February 1489.
The region was conquered by a succession of neighbouring powers or invaders, including Sassanid Persians, the Byzantine Empire, the Arabs, the Seljuq Turks, the Georgians, the Mongols, the Timurids, the Kara Koyunlu and Ak Koyunlu Turkoman tribes, and finally Safavid Iran.
The Ak Koyunlu and Kara Koyunlu, like many other royal dynasties in Eurasia, put their tamga on their flags and stamped their coinage with it.