April, 1983 – The German news magazine, Stern, announced discovery of Hitler's diaries

The documents were later exposed as forgeries, triggering one of the most spectacular media scandals in history. Experts believe that Hitler never kept a diary.

April, 1925 – Franz Kafka published his landmark novel The Trial

The text, which was initially published as Der Process, is a nightmarish account of a man being arrested and prosecuted by a faceless authority for an unknown crime.

April, 1961 – Sierra Leone became an independent republic

The West African country's first Prime Minister, Sir Milton Margai, ended over 150 years of British colonial rule.

April, 2001 – Dennis Tito became the first space tourist in history

A Russian rocket transported the Californian billionaire to the International Space Station (ISS).

April, 1975 – Hubert van Es took the famous picture of a helicopter airlift from a Saigon rooftop

The image shows South Vietnamese civilians employed by the U.S. trying to escape Saigon on the day before the city's fall. It came to symbolise the American defeat in Vietnam.

April, 1789 – George Washington became the first U.S. President

Washington took the oath of office on the balcony of Federal Hall in New York City. In the United States, he is venerated as one of the country's founding fathers.

May, 1840 – The world's first adhesive postage stamp was issued in the United Kingdom

The Penny Black shows a portrait of Queen Victoria. Despite its historical significance, the stamp can be bought for around £25 as over 68 million copies were distributed.