António Dembo joined UNITA in 1969. After traveling throughout Africa on behalf of UNITA, he returned in 1982 to become commander for the Northern Front and later the Northern Front chief of staff. He became UNITA's Vice President in 1992 when the Angolan Civil War resumed, succeeding Jeremias Chitunda, who was assassinated by the Angolan government in Luanda that year. He also became the general in charge of UNITA's Special Commandos, the Tupamaros.