The International Geoscience Programme Project #512 (Neoproterozoic Ice Ages) was conceived to contribute towards a global synthesis of current geological data on the number, duration, extent, causes and consequences of glacial episodes during the Neoproterozoic Era. IGCP 512 attracted more than 200 scientists from over 30 countries, many of whom provided their regional and specialist expertise on Neoproterozoic successions around the world to the realization of this volume. IGCP 512 focused on integrating various aspects of Neoproterozoic geology: geochronology, geochemistry, sedimentary geology, biostratigraphy, palaeomagnetism and economic geology. At its inaugural meeting on August 27th, 2005 during the International Association of Sedimentology conference on glacial processes and products in Aberystwyth, Wales, IGCP 512 members decided to produce a volume that summarized existing datasets in a form similar to Earth’s Pre-Pleistocene Glacial Record by Hambrey & Harland (1981). An enormous amount of work has been carried out in the past 12 years since the publication of Hoffman et al.’s (1998) paper on the snowball Earth hypothesis for Neoproterozoic glaciation (Fairchild and Kennedy 2007). The snowball Earth hypothesis and, more generally, Neoproterozoic climate, have been the topic of numerous special volumes, special sessions, a dedicated conference in Ascona, Switzerland, in 2006 (Shields 2006), and numerous documentaries. Motivated by this intense worldwide interest in the Neoproterozoic glaciations and an exploding body of research into the topic, this volume synthesizes the state-of-the-art in this now highly multidisciplinary research field. It is intended to facilitate integration of datasets, inspire new research projects, and inform ongoing work into the definition and subdivision of the Neoproterozoic time scale, including selection of the Global Stratotype Section and Point (GSSP) for the base of the Cryogenian Period. Despite such lofty aims, any book such as this cannot claim to be complete, and there are indeed many gaps in our knowledge and also in this book’s coverage, some of which are outlined in this Introduction and throughout the volume.