After Prince Vasilko died in the Battle of Sita on March 4, 1238, Beloozero, assigned to his youngest son, separated and formed an independent principality. At this time, Gleb was barely 14 years old. Many trials befell the young prince. The fight against the remnants of pagan beliefs and participation in princely strife, trips to the Horde and joint campaigns with the khan’s troops against the rebellious peoples of the Caucasus - these and other events formed the basis of a new novel by the famous writer-historian.