April 15 - Edward Howard's play The Change of Crowns receives its première in London. Actor John Lacy improvises a few lines about influence-peddling at court, angering King Charles II, a member of the audience (as is Samuel Pepys). The theatre is closed for a time, and Lacy is jailed.
April 27 - The blind, impoverished, 58-year-old John Milton seals a contract (one of the first detailed contracts between author and printer known in England) for publication of Paradise Lost with London printer Samuel Simmons for an initial payment of £5. The first edition is published in October and sells out in eighteen months.