Hussein Mohammed was a Muslim as well as a Nubian and/or Kakwa. At some point, he joined the Uganda Army, and rose in the ranks despite being illiterate, serving as corporal by 1968. Ugandan Colonel Bernard Rwehururu speculated that Hussein was deeply involved in the preparations of the 1971 Ugandan coup d'état which brought Amin to power. He quickly rose to higher commands under the new regime, though the exact timing of his promotions is disputed. Rwehururu stated that Hussein was directly promoted to lieutenant colonel after the coup, whereas businessman Conrad Nkuutu claimed that Hussein was colonel and served as "Garrison Commander" of the Gaddafi Barracks in Jinja by 1973. Journalist Faustin Mugabe described Hussein as lieutenant colonel and "Commanding Officer" in Jinja by March 1974. In contrast, the BBC reported that Hussein was still major by 1975, and was appointed lieutenant colonel in April of that year.