Complex sentence: On 7 July the 2nd New Zealand Division was brought forward from reserve and their attack together with the British 6th Armoured Division eventually took the high ground and caused the German Corps to withdraw towards the Heinrich Line behind the River Arno on 15 July.
Split into simpler sentences: On 7 July the 2nd New Zealand Division was brought forward from reserve. The attack led by the British 6th Armoured Division and the New Zealand Infantry Division eventually took the high ground and caused the German Corps to withdraw towards the Heinrich Line behind the River Arno on 15 July.