This Day in History: April 31

2013 - The widest tornado ever recorded hits El Reno, Oklahoma

In May 2013, a tornado with a record-breaking width of 4.2 km (2.6 mi) hit El Reno, Oklahoma. The storm swept over rural areas of Central Oklahoma, claiming nine lives.

2005 - Deep Throat reveals himself

In 2005, former FBI agent Mark Felt publicly admitted that he was the informant known as "Deep Throat" in the Watergate scandal of the 1970s. Felt's insider information helped uncover the dirty tricks of the Nixon administration, ultimately leading to Nixon's resignation.

1961 - South Africa becomes an independent republic

Following international criticism of the country's Apartheid regime, South Africa left the Commonwealth of Nations and became an independent republic in 1961. The system of racial segregation was gradually abolished in the early 1990s.

1879 - Werner von Siemens presents the world's first electric locomotive

In 1879, German inventor Werner von Siemens presented the world's first electric locomotive. His invention was soon used in trams, and in 1881, the world's first electric tram was introduced in Berlin, Germany.

1859 - The Great Clock housing Big Ben starts keeping time

In 1859, the Great Clock at the top of Elizabeth Tower at the north end of the British Houses of Parliament, commonly known as Big Ben, began keeping time. It is one of the world's best-known timekeepers.

1279 BC - Ramesses II becomes Pharaoh of Ancient Egypt (19th Dynasty)

In 1279 BC, Ramesses II, also known as Ramesses the Great, became Pharaoh of Ancient Egypt as part of the 19th Dynasty.

1578 - Martin Frobisher sails from Harwich, England, to Frobisher Bay, Canada

In 1578, English explorer Martin Frobisher set sail from Harwich, England, to Frobisher Bay in Canada. He eventually mined "fool's gold" from the area, which was famously used to pave the streets of London.

1902 - Boer War Ends; Treaty of Unity signed, Britain annexes Transvaal

In 1902, the Boer War ended with the signing of the Treaty of Unity, which saw Britain annex Transvaal in South Africa.

1910 - Union of South Africa declares its independence from the United Kingdom

In 1910, the Union of South Africa was established as a self-governing dominion of the British Empire. It declared its independence from the United Kingdom on the same day.

1916 - Battle of Jutland: Largest naval battle of World War I

In 1916, the Battle of Jutland took place, which was the largest naval battle of World War I. The British Grand Fleet and the German High Seas Fleet clashed in an inconclusive battle that killed 8,645 people. However, it was a strategic victory for the British, and the German fleet never put to sea again in WWI.