[2] As a young man he was educated there and, under the Jesuits, in Kolozsvár (Cluj), which is where he converted from the Calvinist Reformed Church of Hungary to Roman Catholicism in 1583, partly under the influence of his stepmother, a Catholic.

In 1601, he was sent to the Society's establishment at Sellye (today Šaľa, Slovakia), where his eloquence and dialectic won hundreds to Catholicism, including many of the noblest families.

At the initiative of the archbishop and the request of King Matthias II of Hungary, Pope Paul V, by an apostolic brief dated 5 March 1616, granted Pázmány permission to leave the Society of Jesus and to enter the Somascan Clerics Regular; he never left the Jesuit Order, however, so there was only the submission of a request by third parties and the granting of a permission to leave.

As the chief pastor of the Catholic Church in Hungary, Pázmány used every means in his power, short of absolute contravention of the laws, to obstruct and weaken Protestantism, which had risen during the 16th century.

In 1619, he founded a seminary for theological candidates in Trnava, and in 1623 laid the foundations of a similar institution at Vienna, the still famous Pázmáneum, at a cost of 200,000 florins.

[4] Pázmány also built Jesuit colleges and schools at Bratislava (Pressburg), and Franciscan monasteries at Nové Zámky (Érsekújvár in Hungarian) and Kremnica, all located in modernday Slovakia.

He also repeatedly thwarted the martial ambitions of Gabriel Bethlen, and prevented George I Rákóczi, over whom he had a great influence, from allying with the Ottoman Empire and the Protestants.

He received the red hat of a cardinal from the pope on 31 May 1629 at which time he was assigned for his titular church to Saint Jerome of the Croats.

[2] Pázmány died in Bratislava in 1637 and was buried underneath the floor of St. Martin's Cathedral, at the foot of the ancient tomb of St. John the Almsgiver, which he had embellished during his reign.