In the introductory section of La Música en la Corte de Carlos V (Barcelona, 1944), Dr. Higinio Anglés published a series of documents from the Archives at Simancas which showed that a Chapel composed exclusively of Spanish musicians was attached to the Royal Court of Spain as early as 1526 and existed simultaneously with the Emperor's Flemish Chapel from that time. The Spanish Chapel was established by the Empress, Isabel of Portugal, the wife of Charles V, who acted as his regent during his many and prolonged absences from Spain. While the Flemish Chapel regularly accompanied the Emperor on his journeys, the chapel of the Empress belonged to her household and remained permanently in Spain. It is interesting to note the name of Antonio de Cabezón in the first list of cantors of this chapel. The name of the great composer of keyboard music appeared continuously among the musicians attached to the Royal Court until he died in 1566.