Complex sentence: The Panzer-Lehr Division made several counter-attacks, which forced the British out and attacks by the 50th (Northumbrian) Division bogged down in the bocage against the Panzer-Lehr Division.
Split into simpler sentences: The Panzer-Lehr Division made several counter-attacks, which forced the British out. Meanwhile, attacks by the 50th (Northumbrian) Division bogged down in the bocage against the Panzer-Lehr Division.