Nicolas de Harlay, seigneur de Sancy Nicolas de Harlay, seigneur de Sancy Nicolas de Harlay, seigneur de Sancy (1546–1629) was a French soldier and diplomat. Although de Harlay belonged to the Protestant branch of the family of Harlay, he adopted the Catholic religion in 1572 during the massacres of the Huguenots. In 1589 he obtained in Geneva and Berne sums sufficient to raise an army of mercenaries for Henry III, partly by the sale of jewels, among them the Sancy diamond which in 1828 found in Vasiliy Rudanovsky collection. Henry IV made him superintendent of his finances in 1594, but in 1599 he was replaced by
Chastreix-Sancy on and between the Puy de Chabane and Mont Redon, on the west side of the Puy de Sancy, which is part of an ancient stratovolcano which has been dormant for 220,000 years. It is within the Parc naturel régional des volcans d'Auvergne and the commune of Chastreix in the Puy-de-Dôme "département" of the Auvergne "région". It is about 40 km south west of the "préfecture" of the Puy-de-Dôme "département" Clermont-Ferrand, also capital of the Auvergne. The resort is sandwiched between the Cirque de la Fontaine Salée to the south-east and the Val d'Enfer, or Valley of Hell in English,