There are millions of squash players in the world. Unknowingly, they owe a debt to an 18th-century London prison

Squash traces its origins to “rackets,” a prison game created by Fleet Prison inmates in 18th-century London.

Players hit a ball against a wall, and the pastime later spread across Britain.

Harrow School helped refine the game, which eventually evolved into modern squash.

The story shows how a sport born among debtors in a London prison became a global game.