1521-Spanish conquistadors led by Hernán Cortés capture Aztec Emperor Cuauhtémoc in Tenochtitlan, bringing the Aztec Empire to an end 1536-Buddhist monks from Kyoto's Enryaku-ji Temple set fire to 21 Nichiren temples throughout Kyoto in the Tenbun Hokke Disturbance (Traditional Japanese date: July 27, 1536) 1642-Dutch astronomer Christiaan Huygens discovers Mars's southern polar cap 1788-Prussia joins the Anglo-Dutch alliance to form the Triple Alliance to prevent the spread of the Russo-Swedish War of 1788-90 1923-Turkish National Congress selects Mustafa Kemal Atatürk as the first President of Turkey 1937-Second Sino-Japanese War: Japanese forces start the Battle of Shanghai, a three-month conflict involving over one million troops 1942-The Manhattan Project commences under the direction of U.S. General Leslie Groves with the aim of developing an atomic bomb 2015-Swedish prosecutors announce they are dropping allegations against WikiLeaks founder Julian Assange of sexual molestation and coercion