The invasions by the Khwarezmians in 1225 and the Mongols in 1236 terminated Georgia’s "golden age". The struggle against the Mongol rule created a dyarchy, with an ambitious lateral branch of the Bagrationi dynasty holding sway over western Georgia (Imereti). There was a brief period of reunion and revival under George V the Brilliant (1299–1302, 1314–1346), but the eight onslaughts of the Turco-Mongol conqueror Timur between 1386 and 1403 dealt a great blow to the Georgian kingdom. About a century later, its unity was finally shattered by two rival Turkic federations; the Kara Koyunlu, and the Ak Koyunlu. By 1490/91, the once powerful monarchy fragmented into three independent kingdoms – Kartli (central to eastern Georgia), Kakheti (eastern Georgia), and Imereti (western Georgia) – each led by a rival branch of the Bagrationi dynasty, and into five semi-independent principalities – Odishi-Mingrelia, Guria, Abkhazia, Svaneti, and Samtskhe – dominated by their own feudal clans.