Henri Grégoire
Henri Jean-Baptiste Grégoire, often referred to as the Abbé Grégoire, was a French Catholic priest, constitutional bishop of Blois and a revolutionary leader. He was an ardent abolitionist and supporter of universal suffrage. He was a founding member of the Bureau des longitudes, the Institut de France, and the Conservatoire national des arts et métiers.
Biography from
Wikipedia, CC BY-SA 4.0. Portrait: via Wikipedia (see source).