Many saints had moments in their lives where their name was changed, either by their own volition or by a religious superior.
St. Anthony of Padua was one of those saints, as he was born and baptized with the name Ferdinand.
Joining the Order of Friars Minor
Initially Ferdinand felt called to the religious life and joined the Canons Regular of St. Augustine. He kept the name Ferdinand, but was not at peace with the religious order that he joined.
Then one day he attended the funeral of five Franciscans who died a martyr’s death.
Fr. Ubaldus da Rieti narrates the events in his book The Life of St. Anthony of Padua:
Ferdinand, when he beheld the solemn funeral of these five martyrs and the prodigies which God performed through their intercession, became inflamed with ardent zeal to fight for the faith of Christ and shed his blood if need be.
He wanted to join the Franciscans in hopes that he too would be called to become a martyr.
One day he met a few Franciscans and told them his hopes and dreams:
Two religious of the Convent of St. Anthony the Abbot went as usual to the Monastery of the Holy Cross to ask alms for the maintenance of their community. One day Ferdinand approached them secretly and among other things said to them, “I ardently desire to become a member of your order, provided you will allow me to go among the Saracens and thereby have an opportunity to shed my blood for the faith of Christ.“
Ferdinand soon after asked permission from his superior to join the Franciscans. Upon entering the Order of Friars Minor, he was inspired to change his name:
He was not satisfied in having only changed the habit of St. Augustine to that of St. Francis, but wished to change his name also and make himself unknown to his friends and relatives, in order that he might lead a hidden life in Jesus Christ; and he was no longer called Ferdinand but Anthony.
By changing his name to Anthony, he was connecting himself to St. Anthony the Abbot, which was the name of the new monastery he joined.