On the 22nd April 1915, the Second Battle of Ypres began in Belgium.
The German fighter pilot Baron Manfred Albrecht Freiherr von Richthofen, better known as the Red Baron, was shot down and killed.
On the 20th April 1965, workers began painting skylight windows at the Houston Astrodome to limit glare from the sun.
The Treaty of London was signed, which recognised and guaranteed the independence and neutrality of Belgium.
On the night of 18th April 1775, Paul Revere rode from Charleston to Lexington with his message that “the Regulars are coming!”
The Bay of Pigs Invasion was launched by the CIA-sponsored paramilitary group Brigade 2506.
On the 16th April 1922, former First World War enemies Germany and Russia signed the Treaty of Rapallo.
Ninety-six Liverpool Football Club fans died and hundreds more were injured in a crush at Hillsborough Stadium in Sheffield.
On the morning of 14th April 1561, the people of Nuremberg in Germany witnessed a “dreadful apparition” in the sky.
Troops from the British Indian Army committed the Amritsar Massacre when they opened fire on nonviolent protesters and pilgrims at Jallianwala Bagh.
On the 12th April 1945, Harry Truman became the 33rd President of the United States when his predecessor, Franklin D Roosevelt, suddenly died while having his portrait painted.
The Stone of Scone was found on the site of the High Altar at Arbroath Abbey, nearly four months after it disappeared from Westminster Abbey.
On the 10th April 1858 Big Ben – the bell inside the clocktower at the Palace of Westminster in Britain – was cast.
John Hancock, one of Boston’s wealthiest merchants and a leading figure in Boston politics, forcibly removed customs officials from his ship Lydia.