Flemish physician and astrologer. Born in Armentières; died (in Liège ?) after 1587. In 1544 'escrivain et maistre d'escole à Lille'; later physician in Louvain (mentioned c. 1552), Brussels (mentioned in 1565 and 1569), and Liège (mentioned in 1576) (Cf. Biographie Nationale [de Belgique], 8, 1884-85, Columns 744-746, BB, III, pages 402-408). His great specialty was the edition of calendars and almanacs (in Dutch and French). Some of them were printed by Plantin. It may be assumed that of these ephemerides, either printed by Plantin or by other typographers, far more editions were published than the limited number which survived. (Cf. the letter of Plantin to Haschaert, 3 July 1587 [Corr., VIII-IX, no. 1277], regarding the printing of a 'copy' by Haschaert, very probably an almanac for the year 1588. No such publication is known). None of Haschaert's editions by the Plantin Press are entered in the Plantinian catalogues (Ms. 296, M 164, M 321). Edited also: Paracelsus, De la peste et de ses causes et accidents (no. cp010906).