In the aftermath, it was popularly expected in Russia that Apraksin would pursue the Prussian retreat and eventually overrun all of East Prussia; he was, after all, only away from the Königsberg. Inexplicably, the general stopped his advance towards Königsberg and withdrew back into Russia. Historians offer several reasons: after hearing a false report that Empress Elizabeth of Russia had died; to support Peter III as heir to the throne; Apraxin marched on Königsberg but his troops, lacking in supplies, suffered considerable attrition; and, finally, an epidemic of smallpox, which hit the Russian army, especially the Kalmyks, and resulted in 8.5 times more deaths than all the battles fought in 1757.