From British Museum: Martin Droeshout the Younger's name is only familiar because he happened to engrave the portrait of Shakespeare that was prefaced to the First Folio of his Works in 1623 [ULAN states that the Shakespeare portrait is more likely by his uncle, Martin the Elder]. He was the son of Michael, also an engraver, himself the second generation of a family that had emigrated from Brussels to London in about 1570. For the original engraving, see British Museum P,1.226