• 1279 – The Livonian branch of the Teutonic Order suffered a great loss when 71 knights died in the Battle of Aizkraukle.


• 1616 – Nicolaus Copernicus's De revolutionibus orbium coelestium, describing his heliocentric theory of the Solar System, was prohibited by the Roman Catholic Church.

• 1811 – Peninsular War: In the Battle of Barrosa, an Anglo-Spanish-Portuguese force trying to lift the Siege of Cádiz was able to defeat a French attack, although they were ultimately unable to break the siege itself.

• 1872 – George Westinghouse patents the air brake.



George Westinghouse, Jr. (October 6, 1846 – March 12, 1914) was an American entrepreneur and engineer who invented the railway air brake and was a pioneer of the electrical industry, gaining his first patent at the age of 22. Based in Pittsburgh, Pennsylvania for much of his career, Westinghouse was one of Thomas Edison's main rivals in the early implementation of the American electricity system. Westinghouse's electricity distribution system, based on alternating current, ultimately prevailed over Edison's insistence on direct current. In 1911 Westinghouse received the AIEE's Edison Medal "For meritorious achievement in connection with the development of the alternating current system."


• 1936 – The prototype of the Supermarine Spitfire (pictured), a British single-seat fighter that was later used by the Royal Air Force and many other Allied countries during the Second World War, flew for the first time.