Pius leaned heavily on Philip, for by this time Spain had become the acknowledged champion of the church, but he was able to do so without loss of prestige because of the gradual separation of the temporal from the spiritual power.
Among his measures the most noteworthy was one regulating the powers of the college of cardinals, while their exclusive right to elect the pontiff was maintained against the pretensions of the council.

The best Catholic spirit of the time was represented in {386} Cardinal Charles Borromeo, Archbishop of Milan, an excellent prelate who sought to win back members of Christ to the fold by his good example, while he did not disdain to use the harsher methods of persecution when necessary.

Among the amiable weaknesses of Pius was the belief, inherited from a bygone age, that the Protestants might still be reunited to the church by a few concessions, such as those of the marriage of the clergy and the use of the cup by the laity.
[Sidenote: Pius V, 1566-72] With Pius V a sterner spirit entered into the councils of the church.
The election of the Dominican and Chief Inquisitor Michael Ghislieri was a triumph for the policy of Borromeo.

His pitiless hatred of the heretics hounded Catharine de' Medici against the Huguenots, and Philip II against the Dutch.

Contrary to the dictates of prudence and the wishes of the greatest Catholic princes, he issued the bull deposing Elizabeth.