[2][3] Contemporary Mongol sources describe Batu as invading with 12-14 tumens, which would give him a nominal strength of 120.000-140.000 men, mostly nomad cavalry archers.

[2] On the Rus' side, contemporary sources mention only five princes by name,[3] each of whom would be accompanied by his Druzhina, a small retinue of heavy cavalry.

However, these squads, as a rule, did not exceed the number of several hundred men, and were unsuitable for united actions under a single command.

In 1242, Prince Alexander Nevski in Novgorod could muster no more than 1.000 Druzhina and 2.000 militia for the Battle on the Ice.

After receiving envoys of Batu Khan and sending them to their overlord, Yuri II of Vladimir,[7] border princes of Ryazan, Murom, and Pronsk gathered their forces and made a stand on the river Voronezh, waiting for reinforcements from Vladimir.