There is some evidence that Horrocks' father came from the Deane district of Bolton, although this is far from certain, but we do know that his mother was from a notable Toxteth Park family.
Mayroong ilang mga katibayan na Horrocks' ama ay dumating mula sa Deane distrito ng Bolton, kahit na ito ay malayo mula sa mga tiyak, ngunit kung gagawin namin na ang kanyang ina ay mula sa isang taong litaw Toxteth Park pamilya.