This was public knowledge in England by March 1326, and the King openly considered a divorce. He demanded that Isabella and Edward return to England, which they refused to do: "she sent back many of her retinue but gave trivial excuses for not returning herself" noted her biographer, John Parsons. Their son's failure to break with his mother angered the King further. Isabella became more strident in her criticisms of Edward's government, particularly against Walter de Stapledon, Bishop of Exeter, a close associate of the King and Despenser. King Edward alienated his son by putting the prince's estates under royal administration in January 1326, and the following month the King ordered that both he and his mother be arrested on landing in England. While in Paris, the Queen became the head of King Edward's exiled opposition. Along with Mortimer, this group included Edmund of Woodstock, Earl of Kent, Henry de Beaumont, John de Botetourt, John Maltravers and William Trussell. All were united by hatred of the Despensers. Isabella portrayed her and Prince Edward as seeking refuge from her husband and his court, both of whom she claimed were hostile to her, and claimed protection from Edward II. King Charles refused to countenance an invasion of England; instead, the rebels gained the Count of Hainaut's backing. In return, Isabella agreed that her son would marry the Count's daughter Philippa. This was a further insult to Edward II, who had intended to use his eldest son's marriage as a bargaining tool against France, probably intending a marriage alliance with Spain. From February 1326 it was clear in England that Isabella and Mortimer intended to invade. Despite false alarms, large ships, as a defensive measure, were forbidden from leaving English ports, and some were pressed into royal service. King Edward declared war on France in July; Isabella and Mortimer invaded England in September, landing in Suffolk on the 24th. The commander of the royal fleet assisted the rebels: the first of many betrayals Edward II suffered. Isabella and Mortimer soon found they had significant support among the English political class. They were quickly joined by Thomas, Earl of Norfolk, the King's brother, accompanied by Henry, Earl of Leicester (brother of the executed Earl of Lancaster), and soon afterwards arrived the Archbishop of Canterbury and the Bishops of Hereford and Lincoln. Within the week, support for the King had dissolved, and, accompanied by Despenser, he deserted London and travelled west.