Casa de Paços probably owes its name to an ancient paço(*) from the days in which St. Eulália de Rio Côvo might have been a Roman thermal resort. Part of what the estate is today once belonged to the Commendam of Chavão of the Order of Malta, but, for more than 400 years (since the XVI century) and 15 generations it has remained a property of the same family, the Silvas of Rio Côvo, thus named by genealogist Felgueiras Gayo, a descendant himself of this family.
This family later united with the Fonseca family of Amins by matrimony, giving birth to the Silva Fonseca family, who in turn would also unite matrimonially with the Teixeira de Barros family (Majorat of Perdigão), as well as with their relatives Pereira da Fonseca Vilas-Boas (Majorat of Real), the Viscounts of Barrosa and the Mattos Graça family (owners of Casa do Bemfeito and, they too, descendants from the Casa de Paços).
In this house were born and undertook important building works Dr. D. Frei João Baptista da Sylva (1679-1765), Benedictine monk and once General of the Order and, on two different times, General Abbott of Tibães, as well as Dr. Teotónio José da Fonseca (1875-1937), author of Barcelos Aquém e Além-Cávado and of several other monographs and genealogy books, and a member of the Portuguese Archaeologists Association.
(NT: lat. palatiu, hence Engl. palace; also called lat. villa: "a large ancient Roman country house with the buildings and farmland belonging to it" [in the Longman Dictionary of English Language and Culture; Longman: Harlow, 1998])