Siad Barre was a self proclaimed socialist dictator of Somalia from 1969 to 1991. Prior to his presidency he was an army commander under the parliamentary government Somalia inherited from their former Italian colonial overseers.
Barre became an advocate of Russian style Marxist government after spending time with Russian officers in joint training exercises in the early 1960s. In 1969, over accusations of election fraud that greatly diminished his political party's power, the military staged a coup and took over. Barre ruled with an iron fist for the next 22 years, during which starvation, murder and repression were commonplace. As well, he attempted to develop a personality cult- giant posters of him were common in the capital Mogadishu during his reign, many of which can still be seen today. He was finally unseated when the country completely fell apart and no amount of political control was possible at all.
Somalia has had no real national leader since Siad Barre was deposed in 1991, nor any government at all for that matter for over a decade.