Sacadura Botte was born on 31 October 1902 at the family manor of Quinta da Bica, in Seia, Portugal, near Serra da Estrela. He was the fifth and last son of João Pacheco de Sacadura Botte, 8th Lord of Quinta da Bica, and Maria da Ascenção Mendes de Oliva. His father was a magistrate, landowner and winemaker, as well as a monarchist politician and candidate for the Beira region. As a young boy, Theodorico lived through the fall of the Portuguese Monarchy, much to the dismay of his traditional, Catholic and monarchist family, and helped his father in his campaign as monarchist candidate to the government of the region where they lived in Portugal, albeit unsuccessfully.