He adopted the advice, entered with zeal into the study of theology, and soon qualified himself to pass creditably through the exercises necessary to obtain the degree of doctor in theology. He already wore the insignia of his bishopric, but the Pope's sanction was still wanting, and was withheld on account of the extreme youth of the expectant. Resolved to overcome this difficulty, he set off to Rome, addressed the pontiff in a Latin oration, and gave such proofs of talent and acquirements above his age, that he was consecrated at Rome on the Easter of 1607, being as yet but twenty-two years of age.
This position attained, Richelieu endeavored to make the utmost advantage of it. He acquired the good-will of his diocese by rigid attention to the affairs that fell under his jurisdiction; while in frequent visits to the capital, he sought to acquire reputation by preaching. In the Estates General of 1614, he was chosen deputy by his diocese, and was afterward selected by the clergy of the States to present their _cahier_ or vote of grievances to the monarch. It was an opportunity not to be thrown away by the ambition of Richelieu, who instantly put himself forward as the champion of the queen-mother against the cabal of the high noblesse. He at the same time pointed out where she might find auxiliaries, by complaining that ecclesiastics had no longer a place in the public administration, and were thus degraded from their ancient and legitimate share of influence. Richelieu was rewarded with the place of almoner to the queen; and he was soon admitted to her confidence as well as to that of her favorite, the Maréchal D'Ancre.
In 1616 he was appointed secretary of state; but aware by what slender tenure the office was held, he refused to give up his bishopric. This excited not only the animadversions of the public, but the anger of the favorite. Richelieu offered to give up his secretaryship, but the queen could not dispense with his talents. The assassination of the favorite, however, soon overthrew the influence of the queen herself. Still Richelieu remained attached to her, and followed her to Blois; but the triumphant party, dreading his talents for intrigue, ordered him to quit the queen and repair to one of his priories in Anjou. He was subsequently commanded to retire to his bishopric, and at last exiled to Avignon. Here he sought to avert suspicion by affecting to devote himself once more to theological pursuits. During this period he published one or two polemical tracts, the mediocrity of which proves either that his genius lay not in this path, or, as is probable, that his interest and thoughts were elsewhere.