The Long Parliament enacted the Licensing Order in London on 16 June 1643 to control the rapidly expanding press. Publications required prior approval, and authorities could search for illicit presses and punish printers. Parliament thus revived censorship mechanisms after benefiting from the earlier collapse of royal controls.

The order directly provoked Milton's Areopagitica, one of the most influential arguments against pre-publication censorship. It also pushed radical religious and political writers into clandestine publishing networks.