Complex sentence: He opened his first car sales agency in 1913, leading to the global Rootes Group During World War II, he supervised volume manufacture of aircraft and engines, as well as the supply of military motor vehicles and armoured fighting vehicles.
Split into simpler sentences: He opened his first car sales agency in 1913, leading to the global Rootes Group. During the Second World War he supervised the volume manufacture of aircraft and engines, as well as the supply of military motor vehicles and armoured fighting vehicles.