Joannes Busaeus

Joannes Busaeus or Johannes Busius (1547–1611), also known as Jan Buys (Dutch) and Jean Busée (French), was a Catholic theologian from the Habsburg Netherlands who wrote in defence of the introduction of the Gregorian calendar in Germany, and produced the first printed edition of the "Liber Pontificalis".
Life.
Busaeus was born in Nijmegen on 14 April 1547. He entered the Society of Jesus in 1563. He was a student at the University of Mainz in the 1560s, and continued to teach Theology there until his death. He died in Mainz on 30 June 1611.