Battle on the Irpin River

The Battle on the Irpin River occurred in early 1320s between the armies of Gediminas, the Grand Duke of Lithuania, and Prince (knyaz) Stanislav of Kiev, allied with Oleg of Pereyaslavl' and Roman of Bryansk. On the small Irpin River about 23 km south west of Kiev, Gediminas resoundingly defeated Stanislav and his allies. He then besieged and conquered Kiev sending Stanislav, the last descendant of the Rurik Dynasty to ever rule Kiev, into exile first in Bryansk and then in Ryazan. Theodor, brother of Gediminas, and Algimantas-Michael, son of Mindaugas from the Olshanski family, were installed in Kiev.

As the result of these events the rulers of Kiev and other lands that used to be in the heartland of Kievan Rus' had to accept the seniority of Lithuanian Grand Dukes. However, an account from 1331 possibly shows that Theodor was still paying a tribute to the Mongols. Lithuanians gained full control of the city only in 1362 after the Battle of Blue Waters against the Golden Horde.

Historical basis
For a while historians did not believe that the battle actually took place. Information about it comes from generally confused and unreliable Ukrainian and Lithuanian Chronicles. No other sources actively collaborate with the story, many names mentioned in the chronicles do not appear anywhere else, details of the account are borrowed from earlier and later campaigns. However, more careful analysis of all available sources would show that while details and names are confused and tangled, the story has basis and should not be dismissed outright.