This book examines the development of a national identity and the ideology of nationalism, and the formation of nation-state in Iraq under the British Mandate from 1920 to 1932. The study focuses on the influences of the early Arab nationalist movements during the last decades of the Ottoman Empire and under the British Mandate over Iraqi nationalism and nation-state process. The study specifically examines the Mosul question and its effects on the formation of the territorial unity of the state in Iraq. The study also explores the successive civil administration during Mandate period while making Iraq a “nation-state” by taking actions concerning the politics, social structure, the government, army and economy. The British Mandate period in Iraq witnessed many important developments such as the drawing of Iraq’s boundaries and the shaping of the foundations of the state structure. These developments continue to affect the country in a variety of ways even today. In the final part of the book, it is pointed out that understanding some of the policies and strategies implemented in Iraq by the British can help to make meaningful interpretations of current affairs in this country.