Complex sentence: The edge of the villages was carried, but in the interior a murderous struggle began, every foot of ground being contested, after a time William himself, leading a heavy counter-attack, expelled the assailants from both villages.
Split into simpler sentences: The edge of the villages was carried, but in the interior a murderous struggle began, every foot of ground being contested. After a time William himself, leading a heavy counterattack, expelled the assailants from both villages.