Second marriage to Geoffrey de Mandeville, 2nd Earl of Essex

On 20 January 1214, Isabella of Gloucester entered her second marriage, to Geoffrey FitzGeoffrey de Mandeville, 2nd Earl of Essex. This marriage was arranged and sold by King John, who by this time had annulled his own marriage to Isabella (in 1199) but had retained control over her person and her valuable Gloucester estates as a royal ward and heiress. John profited enormously from brokering her hand: Geoffrey de Mandeville reportedly paid a very large sum—said to be as much as 20,000 marks—for the privilege of marrying Isabella and gaining access to her inheritance.

This transaction exemplifies the medieval practice of treating wealthy widows and heiresses as valuable commodities in the king's gift, to be married off for political loyalty and financial gain. Isabella, despite her rank as former queen consort and substantial landholder in her own right, had little personal agency in the arrangement; her marital fate remained tied to the Crown's fiscal and political needs even a decade after her first marriage ended.

The marriage briefly elevated Geoffrey de Mandeville to great wealth and status as Earl of Essex through his wife's holdings, but it proved short-lived: Geoffrey died in 1216 during a tournament, once again leaving Isabella widowed and in possession of her rich estates, setting the stage for yet another arranged match in the final year of her life.