Assembled in this article are biographical data concerning the painter Gillis I Coignct (Gillis met de Vlek) which are based on and have been confirmed by recent archival research. The year of the artist's birth can now be established as I542. He was a son of the goldsmith and instrument maker Gillis Coignet. Coignet became a master in I56I, travelled to Italy and by I570 had returned to Antwerp, where he had several pupils and served as a dean in the painters' guild. Judging by tax-registers, he was fairly well-to-do In I586 he left Antwerp for Amsterdam, moving on to Hamburg circa I595. He died there on December 27 I599. The article also presents some data pertaining to relatives of Gillis I Coignet, some of whom were likewise painters.