Complex sentence: He is given the Third Army and distinguishes himself by rapidly sweeping across France until his tanks are halted by lack of fuel, and later relieving the vital town of Bastogne during the Battle of the Bulge.
Split into simpler sentences: He is given the Third Army and distinguishes himself by rapidly sweeping across France until his tanks are halted by lack of fuel. He later relieves the vital town of Bastogne during the Battle of the Bulge.