Serge Dassault, billionaire businessman and politician who led Dassault Groupe, died at his Paris office of heart failure today at 2 p.m. GMT (10 a.m. EDT). He was 93. One of two children of company founder Marcel Dassault, who began his career by designing a propeller for World War I pursuit airplanes, Serge Dassault was honorary chairman of Groupe Industriel Marcel Dassault, the family’s holding company. The group includes Dassault Aviation, makers of the Rafale fighter and Falcon business jets, as well as software giant Dassault Systèmes.

Serge Dassault also owned France’s oldest newspaper, Le Figaro, and forged a reputation as a staunchly conservative politician, having held office as mayor of Paris suburb Corbeil-Essonnes and later as a French senator. In 2016, his net worth was listed as $15 billion by Forbes.

Under Dassault’s leadership, the family business has forged a reputation for innovative engineering, not only in its aviation products, but also in design software, notably its Catia program. In aviation, Dassault has blended its engineering expertise in military and civilian programs to produce some of the most advanced aircraft and systems in the industry.

After Dassault passed on the reins of the family business to CEO Charles Edelstenne in 2014 (himself succeeded by Eric Trappier), he remained active in the family business. Serge Dassault is survived by four children; Olivier, Laurent, Thierry, and Marie-Helene.