The IUM was founded in Tripoli in 1982 from a splinter faction of the Lebanese Islamic Group led by Sheikh Said Shaaban, one of Lebanon’s Islamist movements’ few charismatic Sunni religious leaders. A hardliner who believed that force was a good solution in politics, the radical Shaaban broke away from the Islamic Group soon after the June 1982 Israeli invasion of Lebanon, in protest for that Party’s leadership decision of adopting a non-violent, moderate political line in the early 1980s. Nevertheless, the two organizations have always maintained a good relationship, especially with Sheikh Fathi Yakan, founder and Secretary-general of the Islamic Group.