This introduction presents an overview of key concepts discussed in the subsequent chapters of this book. The book begins by describing the area that became Iraq from ancient times through the Ottoman Empire. It explains traditional forms of social organization, the differences and similarities between Iraq's Sunni and Shia Arabs, and the distinctive history and characteristics of the large ethnic minority, the Kurds. The book describes Iraq during the 1920–1932 British Mandate and the period of formal independence under the British-installed monarchy from 1932 to the 1958 revolution, depicting the constrained nature of political conflict and the contending political groups. It also explains the impact of the Iranian Revolution on Iraq, including Iraqi Shia political religious organizations and the outbreak of the Iran–Iraq War. The book also describes how the Iran–Iraq War, along with other factors, led to Iraq's decision to invade Kuwait and the 1991 Gulf War, and the consequences of Iraq's defeat.