 He gave up the military career to devote full-time to genealogical studies that led to the publication of the important volume in 1631, which was partly financed by the magistrate of the city of Ghent.The work contains the genealogical history of the counts of Flanders with a description of the aforesaid country.The number of illustrations in this book counts to a hefty 1,121 escutcheons, standards and seals of armorial bearings on wood, besides 58 copperplate illustrations.