Complex sentence: He returned home in time to see the French fleet arrive and to join Washington at the siege of Yorktown, where he was given command of a battalion of light infantry on October 1 when its commander was killed.
Split into simpler sentences: He returned home in time to see the French fleet arrive and to join Washington at the siege of Yorktown. He was given command of a battalion of light infantry on October 1 when its commander was killed.