Llewelyn was now as powerful as any Welsh prince had ever been; while England was in the throes of the bitter struggle between the king and the barons led by Simon de Montfort. An alliance was concluded between the Welsh and Simon; and the defeat and capture of Henry at Lewes in May 1258 gave Llewelyn a respite in which to consolidate his gains and to strengthen his position. So long as England remained disunited Llewelyn was perfectly secure, but the death of Simon, and the triumph of the king, altered the whole situation. This Llewelyn knew perfectly well, for he was no idle dreamer; and he was then, as indeed always, willing to come to terms with the king upon the old conditions--Wales to be independent, and the Prince of Wales to do homage to the King of England. In September 1267 Henry led an army to Shrewsbury; and with them came the legate Ottobon, {90} for the purpose of negotiating with Llewelyn. The Welsh prince had now, for some years, been excommunicated. Indeed, throughout the long struggle the Church proved itself to be the implacable enemy of Welsh independence. Recognizing the hopelessness and the futility of war against the whole strength of England, Llewelyn, at Shrewsbury, came to terms with Henry; and four days afterwards the terms were embodied in the Treaty of Montgomery. Llewelyn was to do homage to Henry, and to pay him an indemnity. His own position as Prince of Wales was recognized; and he was to retain possession of the Four Cantrefs. This was the position in 1273, when Henry III died.