Complex sentence: Between 1910 and 1914 he was Headmaster of Repton School after which he returned to being a full-time cleric by becoming Bishop of Manchester in 1921 and Archbishop of York in 1929.
Split into simpler sentences: Between 1910 and 1914 he was Headmaster of Repton School after which he returned to being a full-time cleric. He was appointed Bishop of Manchester in 1921 and Archbishop of York in 1929.