[1][2][3][4] From an old family of magistrates, he was the son of Charles Claude, Marquis du Tillet, Vicomte de Malmaison, brigadier of the king's armies, and Margaret of Coeuret Nesle (whose sister married Charles Flahaut César La Billarderie and another Testu François de Balincourt).
Guillaume Louis studied humanities in Génovéfains of Provins, and theology at the Oratory of Saint-Magloire seminar in Paris, and then fired[clarification needed] at the Sorbonne in 1754.
Commendatory prior, he spent long periods in Tornac and, in these, distributed much revenue its priory poor, including both Catholics and Protestants in the region.
[6] Elected on 28 March 1789, member of the clergy to the States General by the principality of Orange,[7][8] he showed himself very reserved and resigned on 29 October 1789 in favor of the abbot of Poulle, provost of the chapter .
Transferred to Melun and Fontainebleau, reduced to Provins, he suffered from a rather serious ophthalmia, and asked to be taken to hospital or in his castle Blunay: he was released on 27 September 1794 and died two months later.