Léopold-Guillaume de Habsbourg
In 1654 Archduke Leopold Wilhelm of Austria, then-Governor of the Spanish Netherlands, made Marc's brother Jean-Jacques councilor and auditor in the Court of Accounts of Brabant, and councilor in the "Raad van Financiën", managing the domains of the Habsburg ruler and performing the financial management. In addition to the hereditary nobility coupled to this position, Jean-Jacques was granted the title of Knight.