Complex sentence: At the Lorette Spur, the 117th Division was sent forward to relieve the 28th Division on 18 May, with orders to hold at all costs the area from the (mud hollow) to Ablain and the south end of Souchez.
Split into simpler sentences: At the Lorette Spur, the 117th Division was sent forward to relieve the 28th Division on 18 May, with orders to hold the area at all costs. The area from the (mud hollow) to Ablain and the south end of Souchez.