He was likely trained in Mechelen and was later a pupil or assistant in the Antwerp workshop of Cornelis Floris de Vriendt whose work was particularly popular in Northern Europe.
The Baltic region was at the time politically relatively stable when compared to van Egen's native home, the Spanish Netherlands, which were rife with religious persecution.
[4] Frederick II died in 1588 and a year later Gert van Egen was commissioned to make a monumental tomb of the king to be placed in Roskilde Cathedral.
It has been suggested that the design for the tomb was by the hand of the sculptor Johan Gregor van der Schardt who was at the time probably working in Denmark.
[4] In addition to the large-scale tomb of Frederick II, it is recorded that in 1600 van Egen delivered to Christian IV a closet with alabaster pieces.
Probably he has also made some small portrait reliefs of Frederick II now at Rosenborg and the Nationalmuseum in Stockholm and a few similar alabaster works of Danish noblemen.