April 20

1303 – The Sapienza University of Rome is instituted by a bull of Pope Boniface VIII. 1653 – Oliver Cromwell dissolves England's Rump Parliament. 1657 – English Admiral Robert Blake destroys a Spanish silver fleet, under heavy fire from the shore, at the Battle of Santa Cruz de Tenerife. 1657 – Freedom of religion is granted to the Jews of New Amsterdam (later New York City). 1752 – Start of Konbaung–Hanthawaddy War, a new phase in the Burmese Civil War (1740–57). 1770 – The Georgian king, Erekle II, abandoned by his Russian ally Count Totleben, wins a victory over Ottoman forces at Aspindza. 1775 – American Revolutionary War: The Siege of Boston begins, following the battles at Lexington and Concord. 1789 – George Washington arrives at Grays Ferry, Philadelphia, while en route to Manhattan for his inauguration. 1792 – France declares war against the "King of Hungary and Bohemia", the beginning of the French Revolutionary Wars. 1800 – The Septinsular Republic is established. 1809 – Two Austrian army corps in Bavaria are defeated by a First French Empire army led by Napoleon at the Battle of Abensberg on the second day of a four-day campaign that ended in a French victory. 1828 – René Caillié becomes the second non-Muslim to enter Timbuktu, following Major Gordon Laing. He would also be the first to return alive. 1836 – U.S. Congress passes an act creating the Wisconsin Territory. 1861 – American Civil War: Robert E. Lee resigns his commission in the United States Army in order to command the forces of the state of Virginia. 1861 – Thaddeus S. C. Lowe, attempting to display the value of balloons, makes record journey, flying 900 miles from Cincinnati to South Carolina. 1862 – Louis Pasteur and Claude Bernard complete the experiment disproving the theory of spontaneous generation. 1865 – Astronomer Angelo Secchi demonstrates the Secchi disk, which measures water clarity, aboard Pope Pius IX's yacht, the L'Immaculata Concezion. 1876 – The April Uprising begins.