Gortzius Geldorp was a Flemish Renaissance artist who was active in Germany where he distinguished himself through his portrait paintings. Gortzius Geldorp was born in Leuven. The early Flemish biographer Karel van Mander reported that Geldorp first learned to paint from Frans Francken I and later from Frans Pourbus the Elder.
Frans Pourbus the Elder was a prominent portrait painter in Flanders. Frans Francken I and Frans Pourbus the Elder were both pupils of Frans Floris, the leading Renaissance painter in Antwerp.
Geldorp became court painter to the Duke of Terra Nova, Carlo d'Aragona Tagliavia, whom he accompanied on his trips. He travelled to Cologne with the Duke who was participating in peace negotiations with the Dutch Republic. Geldorp stayed in the city while remaining a companion of the Duke on his travels.
In 1610 Geldorp took over the seat of Barthel Bruyn the Younger on the city council of Cologne. Geldorp was a successful portrait painter working for the aristocracy and other prominent patrons.