Historical Events
- Apr 9 Danzig (Gdansk) dike break flood kills 1,200
- Apr 13 The Roman Catholic Relief Act passed by the British Parliament; it was the culmination of the process of Catholic Emancipation throughout the UK.
- Apr 25 Charles Fremantle arrives in HMS Challenger off the coast of modern-day Western Australia prior to declaring the Swan River Colony for the United Kingdom
- Apr 28 Dutch parliament accepts new press laws