Complex sentence: At dawn, Batu, with the help of seven stone throwers, attacked the Hungarian guards on the bridge and after the subsequent arrival of Sejban and his men, the Hungarians retreated to their camp.
Split into simpler sentences: At dawn, Batu, with the help of seven stone throwers, attacked the Hungarian guards on the bridge. When Sejban and his men arrived, the Hungarians retreated to their camp.