 After studying at the Pontifical Roman Seminary, he was ordained to the priesthood by Cardinal Lucido Parocchi on 17 April 1897.From 1897 to 1916, he was a professor at the Pontifical Urbaniana University and then an official of the Sacred Congregation for the Propagation of the Faith.On 14 November 1916, Biondi was appointed Apostolic Delegate to the East Indies and Titular Archbishop of "Dioclea".