On 13 Nov 1362, his fiftieth birthday, King Edward III of England (age 50) created two sons as Dukes ...

Lionel Plantagenet 1st Duke of Clarence (age 23) was created 1st Duke Clarence. Elizabeth Burgh Duchess of Clarence (age 30) by marriage Duchess Clarence.

John of Gaunt 1st Duke Lancaster (age 22) was created 1st Duke Lancaster. Blanche Plantagenet Duchess Lancaster (age 17) by marriage Duchess Lancaster.