He studied the Qur'an under his father, Hajji Hussein Atosh, who was an authority on Islam. Hussein was largely self-educated, and was fluent in both Italian and English.
He took up politics at an early age and was one of the founders of the Somali Youth League. In 1953 he went to Cairo to do Arabic studies at A1 Azhar University, broadcasting frequently on Cairo radio, urging Somalis to revolt against the British. In June 1955 he presented a petition to the United Nations for the Somali Youth League. He returned home in 1956 and was elected president of the party, but quarrelled with other leaders, and left to form the Greater Somalia League in 1958. In the 1959 elections he led a violent campaign against the government and was arrested but was returned to parliament in the same year.
After independence on July 1, 1960, he became Minister of Interior, later being reshuffled to the Communications and Public Works portfolio. He triumphed in the elections of 1964 and though the majority of the SYL was in favour of Abdirashid Shirmarke continuing as Premier, President Osman called for Hussein, who formed his own government. Divisions in the SYL flourished on the system by which members could vote in secret and this led to two years of unstable rule. In 1966 Hussein was defeated on an unimportant issue but continued until the Presidential elctions of 1967 when his ally President Osman was defeated by his predecessor Abdirashid Shirmarke. Shirmarke was then in a position to appoint Egal as Premier and oust his old rival Hussein.
Hussein continued his opposition vigorously in the Assembly, leaving the SYL to form his own Popular Movement for Democratic Action. This party was totally defeated by the SYL in the March 1969 elections with Hussein’s party winning only two seats and all the remaining opposition members deserting en masse to the government. But in October the coup was to come and Hussein found himself detained along with his old opponent Mohammed Egal in the old Presidential guest house at Afgoi. He was released on April 1, 1973.
He was married, and had two daughters and a son.