Isabella of France was the daughter of Philippe IV (best known for wiping out the Knights Templar). Each of her three brothers became king of France, but died without producing any heirs. Isabella was born in 1295 and married Edward II in 1308, a year after he had become king. Isabella was a very intelligent woman and occasionally carried out negotiations on behalf of her husband, especially with her father and brothers.

Edward II is generally regarded as not having been much of a king. He was almost the antithesis of his father, the great warrior Edward I. He did not much like hunting, although he was interested in both horses and dogs. He did not joust, but he liked rowing. He also liked music. All of this set him apart from his barons. He was, however, very generous and he loved his family.

His besetting problem was that he had favourites whom he promoted at the expense of his more senior barons. The first was Piers Gaveston, an obscure Gascon, who became like a brother to the then Prince of Wales. He had been exiled by Edward I and recalled on the king’s death. Edward II was forced to exile him twice more. Gaveston was not above taking advantage of the king’s generosity and humiliating the barons who should have had the preference that he received. None of this seemed to worry Isabella, despite persistent rumours that the two men were in a homosexual relationship.

The third time Gaveston returned from exile, in 1311, he was captured before he could reach Edward II and killed. The king was heart-broken.

After four years of marriage, Isabella gave birth to her first child, the future Edward III, in 1312. England was on the brink of civil war as Edward II sought vengeance for the murder of Gaveston. The king also had problems with the Scots, losing the Battle of Bannockburn in 1314. Edward was now rumoured to have a new lover, Hugh Despenser, who was also a great enemy of those who had murdered Gaveston, although for different reasons. The two of them exacted revenge on their enemies, which led to a time of tyranny. Civil war erupted in 1321.

The end came for Isabella in 1322 when Edward and Despenser, fighting in the north, retreated from the Scots, abandoning her, so that she became cut off from them and the army, and had to make her own retreat. In 1324 fighting broke out with the French over Gascony. Much of Isabella’s property was taken from her on the basis that she was French. Despite this, in 1325 Edward sent her to France to negotiate with her brother, Charles IV, with a view to ending the fighting. Whilst in her brother’s court she became involved with an exile from England, Roger Mortimer, Earl of March.

Mortimer was eight years older than Isabella. Initially Mortimer had been a supporter of Edward II, but the king awarded Despenser land belonging to Mortimer and to other Marcher lords (those who had land on the border with Wales). In 1322 he led the Marcher lords against Edward and Despenser and was captured. His death sentence was reduced to life imprisonment in the Tower. In 1323 he escaped. His cause was still very popular and his escape to France was aided by many supporters. Isabella and Mortimer quickly became lovers, ironically, since she had, a few years earlier, exposed her adulterous sisters-in-law to her father.

The situation for Edward II became increasingly difficult. Isabella had managed to negotiate an agreement to end the fighting, but it required that the king pay homage for Aquitaine to Charles. Edward found himself in a quandary. If he left the country, the chances were good that war would break out while he was gone and he might not be able to return. Instead, he made his son Duke of Aquitaine and sent him in his place.

The young prince was duly sent to France where, after he had paid homage, he remained in his mother’s care. He wrote to his father begging to be forgiven for what must have appeared to be treachery, but the prince had no means of escaping from his mother.

When the scandal of their liaison made it impossible for them to stay in France, Isabella and Mortimer went to Flanders, where they negotiated with the Count of Hainault for the provision of troops to support their invasion of England. In return, Isabella promised that Prince Edward would marry the count’s daughter, Philippa. With the prince an unwilling figurehead, they landed in England on 24th September 1326. They were successful in gaining support once in England and Edward II tried to escape to Wales. He was captured and deposed. He was imprisoned in Berkeley Castle, where he was either murdered or died in 1327. His younger brother Edmund, Earl of Kent, somehow came to believe that he had been removed to Corfe Castle, so the legend of his survival after 1327 persists.

Isabella and Mortimer took their revenge on those who had harmed them, usually in a cruel and bloody manner, particularly in the case of Hugh Despenser, and became little more than wealth grabbing tyrants. Prince Edward was crowned king, but did not rule. Since he was still a minor, this was not unusual in itself, but it could not have taken the new king long to realise that where his father had gone, he could soon follow.

As he did for the rest of his life, Edward III managed to gather people around him whom he could trust. They entered Nottingham Castle on 19th October 1330 and captured Isabella and Mortimer. Mortimer was tried and executed in November. He wasn’t given a second opportunity to escape from the Tower. The king’s mother, however, posed a different problem. For two years she was held at Windsor Castle, then she moved to Castle Rising in Norfolk, where she lived for most of the rest of her life continuing her extravagant ways unabated until she died in 1358.

If you want to know more about Isabella and Mortimer, two very good starting places are The Greatest Traitor by Ian Mortimer and Isabella and the Strange Death of Edward II by Paul Doherty.