Complex sentence: The attack on Longueval met with initial success, as the thin German outpost line was rapidly overwhelmed and by mid-morning, the British troops had fought from house-to-house to the village square.
Split into simpler sentences: The attack on Longueval met with initial success, as the thin German outpost line was rapidly overwhelmed. By mid-morning, the British troops had fought from house-to-house to the village square.