Alyosha Popovich may have been based on a historical Alexander Popovich of Rostov, who served prince Vsevolod the Big Nest and died in 1223 in the Battle of the Kalka River against the Tatars, according to the Nikon Chronicle. Nora K. Chadwick writing in 1932 stated that the historicity of the figure was assured. However, a later commentator raised the specter that the figure may not have existed, his name merely a 15th-century interpolation into the chronicles by influence of epic poetry.