Siege of Kolomna

According to Rashid-al-Din Hamadani, the contemporary historian of the Ilkhanate, Kolomna was the fiercest battle of the entire campaign: Kulkan, son of Genghis Khan, died in battle.^[7] Reasons for Mongol casualties, which were heavier than usual, might be:

• Kolomna was attacked by only a fraction of Mongol force, while the main army was occupied with the siege of Ryazan.^[4]
• Suzdalian forces at Kolomna included almost all the warriors of Vladimir-Suzdal, the strongest state of Kievan Rus' at the time. The Suzdalian capital city of Vladimir was probably left defenceless, as it was taken after just 2 days^[3]-much smaller Ryazan resisted longer, even after the defeat on the Voronezh River.^[5] Soviet historians estimated the Suzdalian army at Kolomna up to 15,000 men.^[8]
• The Suzdalian army was apparently a relief force,^[5] and Voivode Yeremey is specifically mentioned as "captain of the guards",^[4] so it is reasonable to assume that most of Grand Prince Yuri's Druzhina was there as well. So the army had a small, but well equipped core of professional soldiers.

According to The Tale of the Destruction of Ryazan, a few days after the fall of Kolomna, the main Mongol army was suddenly attacked "in the land of Suzdal".^[9] On 11 January 1238, the last remnant of Ryazan defenders, 1700 men under Evpaty Kolovrat, made a last stand for their country. Though probably fictional, the tale of their sacrifice is "one of the greatest epics in the history of Russia".^[10]

• Khrustalev, Denis G. (2008). Русь от нашествия до "ига" [Rus' from invasion to "yoke"] (in Russian) (2 ed.). Saint-Petersburg: Евразия. ISBN 978-5-8071-0302-4.