 Moving into Wales, de Montfort forged an alliance with the Welsh Prince Llywelyn ap Gruffudd, who provided him with soldiers.An attempt by Simon to ship his forces across the Severn estuary from Newport was thwarted when his transports were destroyed by royalist warships, and he returned to Hereford.Prince Edward meanwhile attacked de Montfort's seat at Kenilworth Castle, where the younger Simon de Montfort had been gathering forces to assist his father.