He studied in Kraków, Liège, and for eight years at the University of Perugia in Florence, Italy.

When he returned to the Commonwealth he obtained permission from Rome to establish a monastery for the Order of Camaldolese.

In 1673 Krzysztof Pac succeeded in passing a law stating that the convention of every third Sejm of the Polish–Lithuanian Commonwealth should take place in Grodno, a city in the Grand Duchy of Lithuania.

Instead, Krzysztof Pac helped to launch his nephew's political career; he later continued to sponsor the expansion of the Pažaislis monastery.

In 2003 they were properly reburied in a ceremony led by the archbishop of Kaunas Sigitas Tamkevičius.