The Islamic State of Iraq (ISI) was a militant group that emerged in the early 2000s, following the U.S. invasion of Iraq in 2003. It was originally known as al-Qaeda in Iraq and aimed to establish an Islamic state governed by strict interpretations of Sharia law. The group gained notoriety for its violent tactics and was responsible for numerous attacks against both military and civilian targets. In 2006, ISI declared itself a caliphate and sought to expand its influence in the region. The group faced significant opposition from the Iraqi government, local militias, and international forces. Over time, ISI evolved into the broader Islamic State (IS), which later expanded its operations into Syria and other areas, becoming a major player in the regional conflict.