However, after the position of Ulugh Muhammad strengthened, he began plundering raids: "he ravaged foreign lands, like an eagle, flying far from his nest in search of food[8]".

This caused concern among people in the inner circles of Moscow Principality and they put pressure on Vasily II, so he decided to expel Ulugh Muhammad from Belyov.

[9] It is interesting to note that at that time the Grand Duke of Lithuania was formally suzerain of Belyov, like other Upper Oka Principalities, but they also retained their ties with Moscow.

[12] Going to spend the winter near Belyov, Ulugh Muhammad built near the town a kind of fortification ("ostrog") – wicker walls were covered with snow and watered.

In some chronicles, the main blame is assigned to Grigory Protasyev, voivode of Mtsensk, who allegedly sided with Ulug Mohammed and "made a treason".

[a] During the negotiations on the morning of 5 December, Ulu-Mohammed refused to pay him any tribute and promised not to attack the Russian principalities, and offered his son as a hostage.