The grave situation at home showed the folly of this untimely revival of an active foreign policy. The same years that saw the collapse of Henry’s hopes in Normandy and Poitou, witnessed troubles both in Ireland and in Wales. In both these regions the house of the Marshals was a menace to the neighbouring chieftains, and Hugh de Lacy, Earl of Ulster, and Llewelyn ap Iorwerth, made common cause against it and vigorously attacked their rivals both in Leinster and in South Wales. Nor was this the only disturbance. The summons of the Norman chieftains of Ireland to Poitou gave the king of Connaught a chance of attacking the justiciar of Ireland, Geoffrey Marsh, who ultimately drove the Irish back with severe loss. Llewelyn was again as active and hostile as ever. Irritated by the growing strength of the new royal castle of Montgomery, he laid siege to it in 1228. Hubert de Burgh, then castellan of Montgomery, could only save his castle by summoning the levies of the kingdom. At their head Hubert went in person to hold the field against Llewelyn, taking the king with him. The Welsh withdrew as usual before a regular army, and Hubert and the king, late in September, marched a few miles westwards of Montgomery to the vale of Kerry, where they erected a castle. But Llewelyn soon made the English position in Kerry untenable. Many of the English lords were secretly in league with him, and the army suffered severely from lack of food. In the fighting that ensued the Welsh got the better of the English, taking prisoner William de Braose, the heir of Builth, and one of the greatest of the marcher lords. At last king and justiciar were glad to agree to demolish the new castle on receiving from Llewelyn the expenses involved in the task. The dismantled ruin was called “Hubert’s folly”. “And then,” boasts the Welsh chronicler, “the king returned to England with shame.”