[1] His father was the diamond merchant Barthélemi Marcquis, originally from Wallonia, and his mother Catherine Noppen, a native of 's-Hertogenbosch.

He became part of the late humanist circle around mayor Nicolaas Rockox, which included Gaspar Gevartius, Philip Rubens, Deodat del Monte, Joannes Woverius, Laurentius Beyerlinck, Aubert Miraeus, Jan and Balthasar Moretus, and Franciscus Sweertius.

[1] On 24 November 1610, the physicians of Antwerp adopted Marcquis's proposal to found a College of Medicine which would also function as a professional body and advise the city government on epidemic response and public sanitation.

This Collegium Medicum was eventually founded on 28 April 1620, with Marcquis appointed its first professor of surgery and anatomy.

[1] In 1646 he unsuccessfully applied to the city council to cover the expense of a coach and coachman, since he was no longer able to ride or walk to patients as previously.