Amgueddfa Cymru – National Museum Wales commenced the Palaeolithic Settlement of Wales research project in 1978 with a first season of excavation at Pontnewydd Cave, Denbighshire under the direction of Stephen Aldhouse-Green who became Keeper of Archaeology & Numismatics 1988–1996. The research project led to the investigation and publication of a further six caves across Wales. Prior to the commencement of the Pontnewydd Cave excavations our knowledge and understanding of the Palaeolithic occupation of Wales was very patchy. Archaeological evidence was scanty with just a handful of surface finds and a limited number of excavated site assemblages including Paviland Cave, Hoyle’s Mouth and the Tremeirchion caves. With the National Museum’s research programme this was all to change, as it pushed back the knowledge of a human presence in Wales from 50,000 to 230,000 years ago. The discovery in 1980 of a tooth that Chris Stringer was to identify as Neanderthal transformed the whole nature of the project. The research now attracted funding from many international research bodies and drew together a team of scientists from across the globe who, as the contributors list for this volume demonstrates, are all leaders and highly regarded in their respective fields. In 1984 the first interim report published by the National Museum provided the taster for this long-awaited volume and it is to Stephen and his team’s credit that the research commenced over thirty years ago is now drawn together into this new book. Inevitably scientific knowledge has developed in leaps and bounds after three decades, and the Editors of this book have involved the original scientists as well as embracing a new generation along the way.