Complex sentence: He commanded Churchill tanks in Normandy during the Second World War and during Operation Bluecoat in late July 1944, his was the first Allied unit to encounter German Jagdpanther tank destroyers, being attacked by three out of the twelve of these vehicles which were in Normandy.
Split into simpler sentences: He commanded Churchill tanks in Normandy during the Second World War and during Operation Bluecoat in late July 1944. His was the first Allied unit to encounter German "Jagdpanther" tank destroyers, being attacked by three out of the twelve of these vehicles which were in Normandy.