In the 1230s and early 1240s, as Alfonso entered adulthood, Murcia was a much-coveted jewel: the Castilians, the Aragonese, and the rulers of Granada all had their eyes on this prize. But it was to Castile that its beleaguered ruler had turned for military protection, and on May 1, 1243, the young prince himself occupied the city, taking possession of its fortress.
As king, it would have been especially painful for Alfonso to face the prospect of losing Murcia, as the city revolted against his authority in the so-called mudéjar rebellion (1264). It would have been almost equally painful that he had to rely on the intervention of his father-in-law, Jaume I of Aragón, to recapture the city: the Castilian chronicle does not mention the decisive Aragonese rescue.
In a codicil to his last will and testament, Alfonso asked that his body be interred in one of the two parts of his realm that had remained loyal to him throughout his reign: either in the cathedral of Seville, or in the church of Santa María la Real in Murcia, for this was “the first place that God wished us to gain in His service and in the honor of King Fernando, our father”. In the end, the king’s heart and internal organs were buried there.