During a considerable part of prehistory stone tools were indispensable. Flint in particular had properties that made it very suitable for making razor-sharp implements and could often, but not always, be collected locally. Hunters, gatherers and fishers mostly used small tools but with the transition to an agricultural way of living this situation changed, as larger implements became necessary, to cut down trees and work wood for instance. The raw material suitable for this was often not available locally, so was imported from areas where good raw material was available. It was sometimes extracted on an almost industrial scale and even by underground mining. There are many known places in Europe where this extraction took place thousands of years ago. In the first half of the 1980s it became clear that the island of Heligoland also played a role as a large-scale supplier of flint. Prehistoric tools made from red Heligoland flint and also from tabular Heligoland flint have been found in Denmark, Germany and the Netherlands, sometimes at a distance of more than 300 km from Heligoland. In this book we will describe the research undertaken on various aspects of the use of this flint. The characteristics of the different types, as distinct from flint that does not come from Heligoland, will be discussed. Furthermore, the tools that were made from it, their dating, their possible social and symbolic meanings, and the transport that took place partly by sea, more than 5000 years ago, will be described. This book is intended for archaeologists, archaeological curators but also for anybody else who has an interest in the story of a fascinating prehistoric flint source.