With the support of Cardinal Roberto Bellarmino he graduated in philosophy and theology in the Collegio Romano held by the Jesuits, and he earned also a doctorate in utroque iure.
In 1605, already a priest, Oreggi moved to Faenza where he taught and entered in contact with Maffeo Barberini, Cardinal legate of the near Bologna from 1611 to 1614.
[1] A turning point in the life of Agostino Oreggi was the elevation of Maffeo Barberini to the papacy as Pope Urban VIII in August 1623.
He worked with his colleagues of Congregation of Propaganda Fide in publishing a rebuttal of Islamic doctrine in 1625 and in 1630 to permit the Jesuits to evangelize Japan.
Oreggi was created cardinal priest with the title of S. Sisto in the consistory of 28 November 1633, and on the same day he was appointed Archbishop of Benevento.