After his ordination, Ferdinand was placed in charge of hospitality in his abbey. It was in this responsibility that he first came into contact with the Franciscans. In 1219 he met five followers of St. Francis who were on their way to Morocco to preach to the Muslims. He was strongly attracted by their simple Gospel life style.
Then in February 1220, news arrived that his five Franciscan friends had been martyred in Morocco. Their remains had been gathered together and sent to Portugal, where they were being venerated as relics of martyrs of the faith. The king ordered them to be placed in the Church of the Holy Cross in Coimbra.
Ferdinand meditated upon the heroic response of these Franciscans to the call to live the Gospel of our Lord Jesus Christ, a call that brought them, too, to their cross. He felt embarrassed, for he considered his own life as an Augustinian to be mediocre and filled with compromise. He longed to embrace the heroic life style of the early Friars Minor. He wanted the freedom of a charismatic and joy-filled response to God’s call to leave everything and follow Him.
Ferdinand eventually obtained permission from his superiors to join the Franciscans. He was invested with the Franciscan habit and began to learn the teachings of their holy founder St. Francis. With this new life style, he also took on a new name. He called himself Anthony, after the hermit St. Anthony of the desert to whom the Franciscan hermitage was dedicated.