Complex sentence: Stanisław initially took part in the battle at the head of a private regiment, but when hetman Karol Chodkiewicz died, and hetman Koniecpolski was taken captive, Stanisław took command and ended the multi-day battle quickly, with the Turks being repelled on October 10,1621.
Split into simpler sentences: Stanisław initially took part in the battle at the head of a private regiment, but when hetman Karol Chodkiewicz died, and hetman Koniecpolski was taken captive, he took command. He ended the multi-day battle quickly, with the Turks being repelled on October 10,1621.