After capturing the main parts of Movarounnahr – Sirdarya basin, Zarafshan, Kashkadarya valleys, Bukhara oasis, Shosh and Fergana valleys, Genghis Khan now turned his main attention to the Khorezm region, the center of the Khorezmshah state. He put his sons Jo'chi, Chigatoy, Oktoy (Ugedey) in charge of this campaign. In particular, the khan attached great importance to the conquest of ancient Urganch (Gurganj), the largest city of the Muslim East, where culture and trade flourished.