Complex sentence: He led his unit to within 130km of Baghdad before being relieved of command on April 4,2003 by MajGen James Mattis, the commanding officer of the 1st Marine Division.
Split into simpler sentences: He led his unit to within 130km of Baghdad. He was relieved of command on April 4,2003 by MajGen James Mattis, the commanding officer of the 1st Marine Division.