[1] Both paternal grandparents were professional musicians (his grandfather Leon de Mauny studied violin with Eugène Ysaÿe).
In 1998 de Mauny founded the St Petersburg International Early Music Festival together with violinist Andrei Reshetin as artistic director.
[2] De Mauny left the Festival in 2007 to join Raiffeisenbank in Moscow as head of public relations in charge of sponsorship policy and philanthropy.
In 2011 de Mauny was appointed General Manager of the Perm Opera and Ballet Theatre in the Urals (artistic director Teodor Currentzis).
From 2020 to 2022 Marc de Mauny was General Director of the new Festival Ravel in Saint-Jean-de-Luz, which he established together with Jean-François Heisser and Bertrand Chamayou.