All Fools' Day, also known as April Fools' Day is a day for practical jokes and hoaxes, but only until 12 noon. The earliest recorded association between 1st April and foolishness can be found in Chaucer's Canterbury Tales (1392).
1578 The birth of William Harvey, the English physician who explained the circulation of blood.
1841 The Royal Botanic Gardens at Kew, originally created from the 9 acres of Princess Augusta's botanic garden, were opened to the public.
1854 'Hard Times' began serialisation in Charles Dickens' magazine, Household Words. It was the tenth novel by Charles Dickens and was aimed at highlighting the social and economic pressures of the times.
1873 The British steamer RMS Atlantic (a transatlantic ocean liner of the White Star Line) ran onto rocks and sank off Nova Scotia, killing 547. It remained the deadliest civilian maritime disaster in history until the sinking of the Danish liner SS Norge in 1904.
1908 The The foundation of the Territorial Force, (renamed the Territorial Army in 1920.) It was formed as a volunteer reserve component of the British Army.
1918 The Royal Air Force was formed. It incorporated the Royal Flying Corps and the Royal Naval Air Service.
1933 English cricketer Wally Hammond set a record for the highest individual Test innings of 336 not out, during a Test match against New Zealand.
1935 Green Belt legislation was introduced to stop indiscriminate building on many areas of the countryside.
1949 The 26 counties of the Irish Free State became the Republic of Ireland.
1969 The Hawker Siddeley Harrier entered service with the Royal Air Force.
1973 Britain introduced VAT (Value Added Tax). It replaced Purchase Tax and Selective Employment Tax.
1980 Britain's first nudist beach opened at Brighton.
1983 Tens of thousands of peace demonstrators formed a human chain stretching for 14 miles, lining a route along what the protesters called 'Nuclear Valley' in Berkshire.
1989 Despite threats of non-payment, the Community Charge or Poll Tax was introduced in Scotland
1990 Up to 1,000 prisoners staged a riot at Strangeways Prison in Manchester in a violent protest against overcrowding. It was the longest prison riot in British history and lasted until 25th April. One remand prisoner died.
1998 A world record price for a musical instrument was set when a 1727 Stradivarius violin was sold at Christie's for £947,500.
2000 The Enigma machine, used by the Germans to encrypt messages in the Second World War, was stolen from Bletchley Park, Buckinghamshire. In September, a man identifying himself as 'The Master' sent a note demanding £25,000 and threatening to destroy the machine if the ransom was not paid. In early October 2000, Bletchley Park officials announced that they would pay the ransom, but the stated deadline passed with no word from the blackmailer. Shortly afterwards, the machine was sent, anonymously and with three of its rotors missing, to BBC journalist Jeremy Paxman.