a French monk of the order of Cistercians, was born in 1635. He embraced the monastic life contrary to his inclination, in order to satisfy his vanity and that of his family. After several years he was appointed to the abbey of Sept Fonts. He at first lived in luxury and debauchery, but in 1663 he repented of this course, and proposed to the friars a rigid reform; but they, after reproaching him severely, abandoned him. Eustache then rebuilt his monastery, and soon after, by the example of Rance, he assembled a new society, which submitted to more rigid regulations. He died Oct. 22, 1709. See Hoefer, Nouv. Biog. Generale, s.v.