In Hac Tanta §5

⁵ We joyfully recall those things recorded so faithfully by the writers of that distant period. Among them the bishop Willibald, Boniface's contemporary, who narrated the virtues and deeds of this saintly man and described the beginnings of his mission to the German people. He had devoted himself to the religious life since his youth in Germany, and he experienced the dangers of the apostolic life among barbarian peoples. Thus he understood that he would reap no lasting fruit without the consent and approval of the Apostolic See and unless he received his mission and mandate from it.