Complex sentence: In early July, Schwarzenberg, having received a request from Wellington and Blücher, ordered Wrede to act as the Austrian vanguard and advance on Paris and by 5 July the main body of Wrede's IV Corps had reached Châlons.
Split into simpler sentences: In early July, Schwarzenberg, having received a request from Wellington and Blücher, ordered Wrede to act as the Austrian vanguard and advance on Paris. By 5 July, the main body of Wrede's IV Corps had reached Châlons.