By the spring of 1326 the scandalous relations of Isabella and Mortimer were notorious all over England and France. Charles IV. grew disgusted at his sister’s doings, and gave no countenance to her schemes. Isabella accordingly withdrew from Paris with her son and her paramour, and made her way to the Netherlands. There she found refuge in the county of Hainault, whose lord, William II, of Avesnes, was won over to support her by a contract to marry the Duke of Aquitaine to his daughter Philippa. A large advance from Philippa’s marriage portion was employed in hiring a troop of knights and squires of Hainault and Holland. John of Hainault, brother of the count, took joint command of this band with Roger Mortimer. The ports of Holland and Zealand, both of which counties were united with Hainault under William II.’s rule, offered ample facilities for their embarkation.
On September 23, 1326, the queen and her followers took ship at Dordrecht in Holland. Next day the fleet cast anchor in the port of Orwell, and that same day the expedition was landed and marched to Walton, where it spent the first night on English soil. The gentry of Suffolk and Essex flocked to the standard of the queen, who declared that she had come to avenge the wrongs of Earl Thomas of Lancaster and to drive the Despensers from power. Thomas of Brotherton, the earl marshal, made common cause with the invaders, and Henry, Earl of Leicester, hastened to associate himself with the champions of his martyred brother. A great force of native Englishmen swelled the queen’s host, and reduced to insignificance the little band of Hainaulters and Hollanders. There was no resistance. Isabella marched to Bury St. Edmunds, “as if on a pilgrimage,” and thence to Cambridge, where she tarried several days with the canons of Barnwell. From Cambridge she moved on to Baldock, where she despoiled the chancellor’s manors and took his brother captive. At Dunstable, her next halt, she was on a great highway, within thirty-three miles of London.