Only 10% of the 150 or so known impact craters on Earth date from the early Precambrian Era, a time period covering some 88% of the Earth's history. Yet this Era encompasses fundamental events in the origin and evolution of our planet from the origin of life itself to the development of continents. The papers in this volume were presented at a workshop sponsored by the European Science Foundation Scientific Network on Impact cratering held in Cambridge, UK, in December 1998. The papers outline the present state of scientific understanding of the role impacts may have played in the biological and geological evolution of the Early Earth.