Complex sentence: His father, Arundell Gray Leakey, was the son of grandfather Reverend Arundell Leakey, clergyman in Suffolk and later vicar of Wendron in Cornwall; he had served in the Duke of Cornwall's Light Infantry in the early 1900s.
Split into simpler sentences: His father, Arundell Gray Leakey, was the son of Reverend Arundell Leakey, clergyman in England. Leakey's father had served in the Duke of Cornwall's Light Infantry in the early 1900s.