Ralph Mentherme, Earl of Gloucester

Ralph Menthermer was a knight in the household of Joan of Acre, daughter of King Edward I of England (r. 1272-1307). In January 1297, two years after the death of her husband Gilbert de Clare, 6th Earl of Hertford, Ralph and Joan secretly married.

The marriage enraged Edward I and he had Menthermer thrown in prison. On Joan’s plead and the intervention of Antony Bek, Bishop of Durham, the King relented, and released Menthermer from prison in August 1297. Menthermer was allowed to hold the titles of Earl of Gloucester and Earl of Hertford, during Joan's lifetime. The titles had been taken from Joan's six-year-old son Gilbert de Clare and were returned to the boy upon Joan's death (1307). In 1309 Menthermer was made 1st Baron Menthermer.

At the time of his death he was worth about £30,000, what represented around 0.75% of net national income of £4m. In 2010 he would have been worth £8.3 bn.