February 25

138 – Roman emperor Hadrian adopts Antoninus Pius as his son, effectively making him his successor. 628 – Khosrow II, the last great Shah of the Sasanian Empire (Iran), is overthrown by his son Kavadh II. 1336 – Four thousand defenders of Pilenai commit mass suicide rather than be taken captive by the Teutonic Knights. 1705 – George Frideric Handel's opera Nero premiered in Hamburg. 1836 – Samuel Colt is granted a United States patent for his revolver firearm. 1843 – Lord George Paulet occupies the Kingdom of Hawaii in the name of Great Britain in the Paulet Affair (1843). 1870 – Hiram Rhodes Revels, a Republican from Mississippi, is sworn into the United States Senate, becoming the first African American ever to sit in Congress. 1875 – Guangxu Emperor of Qing dynasty China begins his reign, under Empress Dowager Cixi's regency. 1912 – Marie-Adélaïde, the eldest of six daughters of Guillaume IV, becomes the first reigning Grand Duchess of Luxembourg. 1916 – World War I: In the Battle of Verdun, a German unit captures Fort Douaumont, keystone of the French defences, without a fight. 1918 – World War I: German forces capture Tallinn to virtually complete the occupation of Estonia. 1921 – Georgian capital Tbilisi falls to the invading Russian forces after heavy fighting and the Russians declare the Georgian Soviet Socialist Republic. 1932 – Hitler, having been stateless for seven years, obtains German citizenship when he is appointed a Brunswick state official by Dietrich Klagges, a fellow Nazi. As a result, Hitler is able to run for Reichspräsident in the 1932 election. 1933 – Launch of the at Newport News, Virginia. It is the first purpose-built aircraft carrier to be commissioned by the US Navy. 1939 – As part of British air raid precautions, the first of 2.5 million Anderson shelters is constructed in a garden in Islington, north London. 1941 – The outlawed Communist Party of the Netherlands organises a general strike in German-occupied Amsterdam to protest against Nazi persecution of Dutch Jews.