Had he fathered a son, history would have been so different, for 
          there would have been neither the War of The Roses nor the Princes in 
          The Tower. In only his fourth year he was married to the ten-year old 
          Elizabeth, daughter and heir of William de Burgh, 3rd Earl of Ulster. 
          However, naturally this marriage was not consummated until 1352 when  
          he was fourteen.                                                      
               Prior to 26 January 1347 in her right, he was recognised as Earl 
          of Ulster and acquired vast estates in Ireland. On 1 July 1345 when a 
          mere child, he had been made Guardian of England and, before April    
          1361, was nominated Knight of the Garter. On 13 November 1362, he was 
          created Duke of Clarence.                                             
               His wife died in 1363 leaving him with an only daughter. His     
          second marriage, to Violante Visconti, was contracted in Westminster  
          on 15 May 1367 and, with great state, was celebrated in Milan on 28   
          May 1368. However, he died on 17 October 1368 aged only twenty-nine.  
          His widow married Secondotto, Marchese de Monferrato, and, after his  
          demise, her first cousin, Lodovico Visconti, Lord of Lodi; she died in
          November 1386 in Pavia.

Source: Leo van de Pas