He was the only son of Francisco Coelho do Amaral Reis, 1st Viscount of Pedralva by Carlos I of Portugal in 1904 (Sátão, Águas Boas, 3 August 1873 – 5 April 1938), 100th Governor of Portuguese Angola from 1920 to 1921, son of José Caetano dos Reis and wife Lucrécia Coelho do Amaral, and first wife, as her second husband, Guida Maria Josefina Cinatti Keil, daughter of Alfredo Cristiano Keil and wife Cleyde Maria Margarida Cinatti.