The importance of Santiago as the brother of Christ and as a supernatural force, ‘invincible and victorious,’ served as a point of support for the impetus of the Reconquest. The course of life intensified the belief, … and it gave rise to forms of worship which today would be judged heterodox.Américo CastroThe subject of this study is all the hymns written for the cult and liturgy of St. James the Greater that are published in the Analecta hymnica medii Aevi. While this source is not exhaustive, it does represent an important part of the hymnological material devoted to this saint. This study is relevant since St. James was a powerful force in the Middle Ages and especially in Spain. Indeed, Américo Castro considers this cult as an ‘axis’ of Spanish history, because the shrine at Compostela not only opened up Spain by bringing pilgrims from all over Europe, but also gave it an identity as a nation which it lacked during the Visigothic era.