Battle of Ostrołęka

:"For the 1807 French Napoleonic victory, see Ostrołęka#History" Infobox Military Conflict
conflict=Battle of Ostrołęka


caption=Battle of Ostrołęka of 1831 by Karol Malankiewicz
partof=November Uprising
date=May 26, 1831
place=Ostrołęka, Poland
result=Polish defeat
combatant1=flag|Poland
combatant2=flagicon|Russia Imperial Russia
commander1=flagicon|Poland Jan Zygmunt Skrzynecki
commander2=flagicon|Russia Hans Karl von Diebitsch
strength1=30,000, 74 cannons
strength2=35,000, 148 cannons
casualties1=6,400 (incl. ~2,000 killed)
casualties2=5,800|

The Battle of Ostrołęka of May 26, 1831, was one of the largest engagements of Poland's November Uprising. Throughout the day, Polish forces under Jan Skrzynecki fought for the control over the town of Ostrołęka against the assaulting Russian forces of Hans Karl von Diebitsch. Although by the end of the day the town was still in Polish hands and the two sides suffered comparable losses, the battle is usually considered a Polish defeat because of the Russian army's almost unlimited strategic reinforcement capability. The Polish Army could not similiarily replenish its casualties. In the event, surviving Polish forces were saved by the particularly brave stand of its 4th Infantry Regiment, the "Czwartacy", who repelled several waves of enemy infantry and cavalry charges, holding the burning town during heavy fighting in close quarters. By late evening the Poles were again saved by a self-sacrificing charge of the 4th battery of mounted artillery led by Lt.Col. Józef Bem.

The battle became one of the symbols of the failed uprising. Julius Moser, a German poet and writer, commemorated the 4th Regiment in his poem "Die letzten Zehn vom vierten Regiment" ("The last 10 of the 4th Regiment"), later widely-translated onto several languages. The battle also inspired Johan Sebastian Welhaven's "Republikanerne".