One of Edward III’s many grandchildren, Philippa de Coucy (born before April 1367) was the daughter of the important French nobleman Enguerrand, Lord of Coucy, by Isabella, eldest daughter of King Edward and Queen Philippa. Isabella was pretty much the definition of a spoiled princess, and contrary to the usual stereotype, pretty much did as she liked. (Isabella did not marry until she was 33, and had previously walked away from one potential husband at the last minute without apparently receiving any censure, let alone punishment, from her father.)
Enguerrand was for a time of the English allegiance, but later returned to France. His wife split her time between the countries, despite the little matter of the on-off war between them.
As for Philippa, she was betrothed to Robert de Vere at a very early age and married to him long before she was of an age for consummation. De Vere was Earl of Oxford, which was at once the oldest and least-well endowed earldom in the country. This was of course a typical business arrangement. Neither Philippa nor Robert had any say in the matter, but that was in accordance with the custom for noble families.
Robert de Vere was highly favoured by Richard II, and he was successively created Marquess of Dublin (a new rank in the English peerage) and Duke of Ireland. As part of the latter promotion he was given the island of Ireland with all its revenues, Richard retaining only the suzerainty.
Robert’s rapid advancement attracted hostility from large sections of the nobility, not least the King’s uncles. However, what really brought matters to a head was de Vere’s decision to annul his marriage to Philippa. It appears he achieved this by submitting false information (and no doubt a suitable cash donation) to the Pope.
His purpose—and I have no doubt that it was this was at the root of the anger generated—was to marry Agnes Lancecrona, one of damsels who had followed Queen Anne from Bohemia. We know very little about Agnes, but it seems certain she was penniless, or very nearly so. She was in charge of the Queen’s jewels, however, so cannot have been, as some chronicles suggest, a woman of low birth.
The ‘divorce’ came through. Philippa found refuge with her mother-in-law, the Countess of Oxford, who stood by her and regarded her as a daughter. Meanwhile, it appears de Vere abducted Agnes from the Queen’s household—not necessarily without her consent—took her up to Chester and (probably) went through a form of marriage with her. Philippa’s uncles, the dukes of York and Gloucester were outraged, and their brother Lancaster would no doubt have been equally angry had he been in the country instead of fighting in Spain. Gloucester was soon to take up arms against his nephew (or at least his nephew’s supporters) and it may be that the treatment of his niece was a final straw.
De Vere was in Cheshire to recruit soldiers for Ireland, but in the event the political situation forced him to march south to deploy them against Richard II’s opponents. They were defeated at Radcot Bridge in Oxfordshire, and, after a very brief visit to the court, de Vere was forced to flee abroad. Convicted of treason by a hostile Parliament dominated by his enemies, he was never able to come home. He died in late 1392 from injuries received in a boar hunt. What happened to Agnes is unknown.
By this time, Philippa’s ‘divorce’ had been reversed by the Pope. (1389). She received a share of Robert’s lands to support her, and was never known as anything other than the Duchess of Ireland. This was her consolation. For a very short time she was placed by her cousin, Henry IV, as the governess of Queen Isabella, Richard II’s very young widow, but apart from this Philippa seems to have been content to live in obscurity. She chose not to marry again, and continued in peaceful retirement until her death in October 1411.