Batu Khan returned to the lower region of Idyll in the year of 1241 and established the headquarters of his "Horde" (military encampment) in the left coast of the river. This place was called as Saray and it substituted the cities of Bulgar and Idyll before long. As a difference of it, it became the most important political centre of the Western Sibir together with the environs of the Eastern Europe, Caspian Sea and the Sea of Aral. The place on which the city of Saray had been founded was determined with great care an accuracy since it was located in the middle of "Cuci's Lands" and on the great trade routes. Therefore, it had developed within a short period.