Battle of Beresteczko, (June 28–30, 1651), military engagement in which the king of Poland, John Casimir (reigned 1648–68), inflicted a severe defeat upon the rebel Cossack leader Bohdan Khmelnytsky. In 1648 Khmelnytsky organized an insurrection among … UWAGA! Z powodu braku rozporządzenia oraz ewentualnych rekomendacji Ministerstwa Sportu, a także braku pewności co do możliwości przekraczania granicy Polski przez obcokrajowców odwołujemy organizację zawodów w dniu 6 czerwca. Battle of Berestechko - International IDPA match Tier II. The Battle of Berestechko (Polish: Bitwa pod Beresteczkiem; Ukrainian: Берестецька битва, Битва під Берестечком) was fought between the Ukrainian Cossacks, led by Hetman Bohdan Khmelnytsky, aided by their Crimean Tatar allies, and a Polish army under King John II … In the early 20th century, it was decided to create a memorial complex to commemorate killed warriors on the place of the token battle. The Battle of Berestechko was the largest battle of the National Liberation War of Ukrainian people and remained the largest one in Europe’s history until the middle of the 19th century.