Events February 18 - George, Duke of Clarence, convicted of treason against his older brother Edward IV of England, is privately executed in the Tower of London. April 26 - The Pazzi attack Lorenzo de' Medici and kill his brother Giuliano during High Mass in the Florence Cathedral. December 28 - Battle of Giornico - Swiss troops defeat the Milanese. Lorenzo de' Medici becomes sole ruler of Florence Grand Prince Ivan III of Moscow conquers Novgorod Vladislav II of Bohemia makes peace with Hungary Births February 7 - Sir Thomas More, statesman and humanist, author of Utopia (d. 1535) December 6 - Baldassarre Castiglione, italian writer and diplomat (the author of The Book of the Courtier - d. 1529). Pope Clement VII (d. 1534) Deaths February 18 - George, Duke of Clarence, younger brother of Edward IV of England. April 26 - Giuliano di Piero de' Medici killed in Florence Cathedral
