Born at Blackburn, Lancashire, on 4 September 1882, the eldest of the two sons and three daughters of George Ollerenshaw, JP, merchant, of Cherry Tree near Blackburn, and his wife Hannah Higginbottom. His father later lived at Glossop, Derbyshire. Ollerenshaw was educated at Manchester Grammar Schoo

Born at East Hoathly, Sussex on 18 September 1884, where his father and grandfather had practised, he was educated at Eastbourne College and Gonville and Caius College, Cambridge. There he took second class honours in the Natural Sciences Tripos part I in 1905, and following the family tradition did