Born in Delft during the Dutch Revolt, Hugo was the first child of Jan de Groot and Alida van Overschie.
At age sixteen he published his first book: a scholarly edition of the late antique author Martianus Capella's work on the seven liberal arts, Martiani Minei Felicis Capellæ Carthaginiensis viri proconsularis Satyricon, in quo De nuptiis Philologiæ & Mercurij libri duo, & De septem artibus liberalibus libri singulares.