The Battle of Ula or Battle of Chashniki was fought during the Livonian War on 26 January 1564 between the Grand Duchy of Lithuania and the Tsardom of Russia on the Ula River (tributary of the Daugava River) north of Chashniki in the Vitebsk Region. The Lithuanian surprise attack resulted in a decisive defeat of the numerically superior Russian forces.
Livonia was invaded by the Russian army of Tsar Ivan IV. After the defeat in the Battle of Ergeme in 1560, the weakened Livonian Order was dissolved and the Duchy of Livonia and Duchy of Courland and Semigallia were ceded to the Grand Duchy of Lithuania according to the Treaty of Vilnius (1561). Russia then launched a campaign against Lithuania, capturing Polotsk in February 1563 and threatening further invasion against Vilnius, the capital city. The Lithuanians attempted to negotiate a truce, but the talks failed in November 1563.
Two large Russian armies from Polotsk and Smolensk, commanded by Pyotr Ivanovich Shuysky and Pyotr Semenovich Serebryany-Obolensky, were to meet near Orsha and jointly march against Vilnius. The army was well-prepared for a long campaign; Velikiye Luki received supplies sufficient to provide the army for half a year. Skuysky moved on on January 23, 1564. Mikołaj "the Red" Radziwiłł, Grand Lithuanian Hetman, who at the time was in Lukoml, quickly organized cavalrymen without waiting for infantry or artillery. His men included Field Hetman Hrehory Chodkiewicz and many future military leaders: his 16-year-old son and future Grand Hetman Krzysztof Mikołaj "the Thunderbolt" Radziwiłł, future Field Hetman Roman Sanguszko, future Livonian Hetman Jan Hieronimowicz Chodkiewicz, and others.