On the death of his wife Constantina in 1327, Don Juan Manuel strengthened his position by marrying Doña Blanca de La Cerda y Lara; he secured the support of Juan Núñez, "alférez" of Castile, by arranging a marriage between him and ex-queen Constanza, to the infante of that kingdom, and he entered into alliance with Muhammed IV, Sultan of Granada. This formidable coalition compelled Alphonso XI to sue for terms, which he accepted in 1328 without any serious intention of complying with them; but he was compelled to release Doña Constanza. War speedily broke out anew, and lasted till 1331 when Alphonso invited Juan Manuel and Juan Nuñez to a banquet at Villahumbrales with the intention, it was believed, of assassinating them; the plot failed, and Don Juan Manuel joined forces with Peter IV of Aragon. He was besieged by Alphonso at Garci-Nuñez, whence he escaped on 30 July 1336, fled into exile, and kept the rebellion alive till 1338.