Sir Willem Boreel, 1st Baronet (2 March 1591 – 29 September 1668) was a Dutch diplomat.
[7] Then, from 1650, until his death in Paris on 29 September 1668 he served as Ambassador of the Dutch Republic to France.
He had a local magistrate in Middelburg in the Netherlands follow up on his recollection of a spectacle maker who told Boreel in 1610 about inventing the telescope.
The magistrate was contacted by a then unknown claimant, Middelburg spectacle maker Johannes Zachariassen, who testified that his father, Zacharias Janssen invented the telescope and the microscope as early as 1590.
[5] Boreel's conclusion that Zacharias Janssen invented the telescope a little ahead of another spectacle maker, Hans Lippershey, was adopted by Pierre Borel in his 1656 book on the subject.