On 19 May 1359 , or thereabouts, a double-royal wedding celebration took place at Reading Abbey [Map] whereby two children of King Edward III of England (age 46) were married:

John of Gaunt 1st Duke Lancaster (age 19) and Blanche Plantagenet Duchess Lancaster (age 14) were married. She by marriage Countess Richmond. She the daughter of Henry of Grosmont 1st Duke Lancaster (age 49) and Isabel Beaumont Duchess Lancaster (age 39). He the son of King Edward III of England (age 46) and Philippa of Hainault Queen Consort England (age 44). They were half second cousin once removed. She a great x 2 granddaughter of King Henry III of England.

John Hastings 2nd Earl Pembroke (age 11) and Margaret Plantagenet Countess of Pembroke (age 12) were married. At the time John Hastings 2nd Earl Pembroke (age 11) was a ward of King Edward III of England (age 46) who would enjoy the benefit of the substantial revenue of the Earldom of Pembroke until John came of age nine years later in 1368. She died two or so years later probably of plague. She the daughter of King Edward III of England (age 46) and Philippa of Hainault Queen Consort England (age 44). He the son of Laurence Hastings 1st Earl Pembroke and Agnes Mortimer Countess of Pembroke (age 42). They were half fourth cousins. He a great x 5 grandson of King John "Lackland" of England.