As the tribes prepared to enter Canaan by crossing over to the west side of the Jordan, the Book of Numbers records that the Israelites defeated Sihon and Og, kings east of the Jordan. The tribes of Reuben and Gad requested that they be given land in the territory east of Jordan, because it was suitable for their needs as livestock grazers. In exchange for their promise to help with the conquest of the land west of the Jordan, Moses accepted their request and granted to them and half of Manasseh land east of the Jordan. Following the death of Moses, Joshua became the leader of the Israelites, and with the help of these eastern tribes including Reuben, conquered some of Canaan and assigned the land of Israel to the various twelve tribes.