5 February – In the Second Anglo-Dutch War, warship HMS Saint Patrick is captured less than nine months after being launched, when it fights an action off the North Foreland. Captain Robert Saunders and 8 of his crew are killed while fighting Dutch ships Delft and Shakerlo. The Dutch Navy renames the ship Zwanenburg.[1]
27 April – John Milton seals a contract for publication of Paradise Lost with London printer Samuel Simmons for an initial payment of £5.[6][7][8] The first edition is published in October[7] and sells out in eighteen months.[9]
10 May – A second Conventicle Act, preventing groups of more than five non-followers of the Church of England from assembling, comes into effect with increased incentives for the authorities to prosecute.
George Villiers, Duke of Buckingham, one of the five members of the Cabal ministry (Lords Chudleigh, Arlington, Buckingham, Ashley and Lauderdale), turns himself in after a warrant for his arrest is issued on 25 February on charges of treason (including the casting of the King's horoscope). He is held in the Tower of London[4] for four years before being released on 17 July 1671.
2 July – A Dutch marine force lands near Woodbridge, Suffolk, and prevents Landguard Fort from being reinforced but a direct assault on the fort is beaten off by the garrison, The Duke of York and Albany's Maritime Regiment of Foot, predecessor of the Royal Marines, and hence the first land action fought by marines.
3 July – A Dutch attack on Osleybay fails.
c. 13–17 July – Exceptionally warm spell peaks.[5]
^Lindenbaum, Peter (1995). "Authors and Publishers in the Late Seventeenth Century: New Evidence on their Relations". The Library. s6-17 (3). Oxford University Press: 250–269. doi:10.1093/library/s6-17.3.250. ISSN0024-2160.