Complex sentence: He commanded the brigade at the Battle of Hazebrouck and in the operations east of Hazebrouck in June and July his brigade was exceptionally active in minor operations and patrolling that became known as peaceful penetration.
Split into simpler sentences: He commanded the brigade at the Battle of Hazebrouck. In the operations east of Hazebrouck in June and July, his brigade was exceptionally active in minor operations and patrolling, and became known as the peaceful penetration.