pardon, possibly from Edward III, but Isabella was insistent on his execution. The execution itself was a fiasco after the executioner refused to attend and Edmund of Kent had to be killed by a local dung-collector, who had been himself sentenced to death and was pardoned as a bribe to undertake the beheading. Isabella de Vesci escaped punishment, despite having been closely involved in the plot. Mortimer's fall from power, 1330 By mid-1330, Isabella and Mortimer's regime was increasingly insecure, and Isabella's son, Edward III, was growing frustrated at Mortimer's grip on power. Various historians, with different levels of confidence, have also suggested that in late 1329 Isabella became pregnant. A child of Mortimer's with royal blood would have proved both politically inconvenient for Isabella, and challenging to Edward's own position. Edward quietly assembled a body of support from the Church and selected nobles, whilst Isabella and Mortimer moved into Nottingham Castle for safety, surrounding themselves with loyal troops. In the autumn, Mortimer was investigating another plot against him, when he challenged a young noble, William Montagu, during an interrogation. Mortimer declared that his word had priority over the king's, an alarming statement that Montagu reported back to Edward. Edward was convinced that this was the moment to act, and on 19 October, Montagu led a force of twenty-three armed men into the castle by a secret tunnel. Up in the keep, Isabella, Mortimer and other council members were discussing how to arrest Montagu, when Montagu and his men appeared. Fighting broke out on the stairs and Mortimer was overwhelmed in his chamber. Isabella threw herself at Edward's feet, famously crying "Fair son, have pity on gentle Mortimer!" Lancastrian troops rapidly took the rest of the castle, leaving Edward in control of his own government for the first time. Parliament was convened the next month, where Mortimer was put on trial for treason. Isabella was portrayed as an innocent bystander during the proceedings, and no mention of her sexual relationship with Mortimer was made public. Mortimer was executed at Tyburn, but Edward III showed leniency and he was not quartered or disembowelled. In retirement, 1330–1358 After the coup, Isabella was initially transferred to Berkhamsted Castle, and then held under house arrest at Windsor Castle until 1332, when she then moved back to her own Castle Rising in Norfolk. Agnes Strickland, a Victorian historian, argued that Isabella suffered from occasional fits