The last grand master did not even reside at Millstatt, and from 1541 onwards the estates were under the rule of Inner Austrian administrators and given in pawn several times.
In 1598 the Inner Austrian archduke Ferdinand II, a devout Catholic, vested the Society of Jesus at Graz with Millstatt.
The abbey even included a nunnery, which was dissolved in the 15th century.
The monastery had definitely been established before 1122, when it was mentioned in a deed issued by Pope Callixtus II.
In the course of the Counter-Reformation, the Jesuits had established a college at the Styrian capital (the present-day University of Graz), that was to be financed with the income of the Millstatt estates.