Belgian businessman who was one of the founders of the S.A. for the Resale of Mass Articles in 1928, more commonly known as Sarma, whose first store offered a new sales technique that had already been successful abroad: the single price. Sarma, of which he became managing director in 1929, soon established three new branches in Namur, Antwerp and Charleroi. Taking advantage of the great crisis which forced consumers to prefer stores with the lowest prices, the company was booming from 1933. Four years later, Sarma employed 4,000 people in 17 stores and 10 restaurants. At the same time, he launched an affiliate chain of independent traders under the Sarma-dépôt brand. Following the law prohibiting the accumulation of wholesale and retail activities, in 1938 he founded S.A. Groothuis, taking over the supply of former Sarma’s affiliates under the Nopri brand. The Sarma and Groothuis-Nopri merged companies in 1966. He was also very active in the representation and defence of employers’ interests, being notably president of the Professional Union of Multiple Department Stores and vice-president of Vlaams Economisch Verbond. His daughter Jeanne married Jacques Dansette, who took over the management of Sarma. Jan-Baptist van Gysel died on 25 April 1956 in Meise at age 71.