Student or Learner
"During Darveau’s final voyage the captain talked to him about his education. He decided to return to Quebec to study theology and was introduced to the archbishop of Quebec, Joseph Signay, in 1838. Although his father refused to go with him to the Grand Séminaire to seek his admission, Darveau entered it on 1 Oct. 1838 upon a promise to Signay that after ordination he would devote himself to mission work. He was ordained on 21 Feb. 1841, in the presence of his family, including his father, with whom he had had a reconciliation.
A man of determined character, with an adventurous and dedicated spirit, Darveau took up the promise made to his archbishop, offering to serve in distant missions. "
What does "took up the promise" mean?
This is an unusual use. I wouldn't recommend copying it, personally.
The writer means that Darveau did what he promised to do.