Dukes of Tancos Duques de Tancos Created by Mary I, Queen of Portugal Decree date 22-04-1790 First holder Constança Manoel, duquesa de Tancos, 2ª marquise of Tancos * bp 1719 Records #1 Holders Family filter On/Off 1 Constança Manoel, duquesa de Tancos, 2ª marquise of Tancos * bp 1719 Sources Nobreza de Portugal e Brasil - 3 vols-vol. 3-pg. 417 Corrections and Updates To suggest a correction or an update. Click Here