Although Hizb ut-Tahrir, an international pan-Islamic political party, regularly holds conferences from Jakarta to Ramallah attended by tens of thousands of people, little is known about the organisation, which was founded in 1953, beyond generalities and conjecture. Its members are repeatedly arrested in Russia, Central Asia, Turkey and across the Middle East, and since the Arab uprisings it has emerged as an influential political actor in Tunisia, has a growing profile in Egypt, and is making a visible impact in the Syrian revolution. It is also paradoxically often dismissed as inconsequential despite its call for the implementation of Islam and the establishment of a universal caliphate across the Muslim world. 'Hizb ut-Tahrir: The Untold History of the Liberation Party' uncovers the history of the global Islamic political party, based upon a diverse array of archival research, internal documents, multiple interviews and other sources to build an authoritative account of the party as told from inside and out. From coup attempts in Jordan, sending delegations to meet Sadat, al-Gaddafi and Khomeini, and the execution of hundreds of its members in Libya and Iraq, Pankhurst's book blends political, intellectual and personal history, moving from global, regional and local perspectives.

While in the West 'the Caliphate' evokes overwhelmingly negative images, throughout Islamic history it has been regarded as the ideal Islamic polity. In the wake of the 'Arab Spring' and the removal of long-standing dictators in the Middle East, in which the dominant discourse appears to be one of the compatibility of Islam and democracy, reviving the Caliphate has continued to exercise the minds of its opponents and advocates. Reza Pankhurst's book contributes to our understanding of Islam in politics, the path of Islamic revival across the last century and how the popularity of the Caliphate in Muslim discourse waned and later re-emerged. Beginning with the abolition of the Caliphate, the ideas and discourse of the Muslim Brotherhood, Hizb ut-Tahrir, al-Qaeda and other smaller groups are then examined. A comparative analysis highlights the core com- monalities as well as differences between the various movements and individuals, and suggests that as movements struggle to re-establish a polity which expresses the unity of the ummah (or global Islamic community), the Caliphate has alternatively been ignored, had its significance minimised or denied, reclaimed and promoted as a theory and symbol in different ways, yet still serves as a political ideal for many.