Gerrard Winstanley was an English Protestant religious reformer, political philosopher, and activist during the period of the Commonwealth of England. Winstanley was the leader and one of the founders of the English group known as the True Levellers or Diggers. The group occupied formerly common land that had been privatised by enclosures and dug them over, pulling down hedges and filling in ditches, to plant crops. "True Levellers" was the name they used to describe themselves, whereas the term "Diggers" was coined by contemporaries.

The Diggers were a group of religious and political dissidents in England, associated with agrarian socialism. Gerrard Winstanley and William Everard, amongst many others, were known as True Levellers in 1649, in reference to their split from the Levellers, and later became known as Diggers because of their attempts to farm on common land. Due to this and to their beliefs, the Diggers were driven from one county after another by the authorities.