30 However, he did not stop at that. In order to assure as much as possible that he would never depart from this rule, he customarily concluded the statutes of his provincial Synods with the following words: "We are always prepared to submit everything we have done and decreed in this provincial Synod to the authority and judgment of the Roman Church, the Mother and Mistress of all the churches." The more quickly he advanced in the perfection of the active ministry the more firmly was he rooted in this resolve, not only when the Chair of Peter was occupied by his uncle, but also during the Pontificates of his successors, Pius V and Gregory XIII. He wielded his influence in having these latter elected; he was tireless in supporting their great endeavors; and he fulfilled in a perfect manner whatever they expected of him.
Source: Editae Saepe (Vatican.va)