Osborne was born in Belfast when his father was Principal of the Collegiate School there, but began his schooling at Dedham when his father was headmaster of the school in that Essex town.
Osborne ay ipinanganak sa Belfast kapag ang kanyang ama ay Principal ng Collegiate School doon, ngunit nagsimula ang kanyang-aaral sa Dedham kapag ang kanyang ama ay punong-guro ng paaralan sa Essex na bayan.