The decline of the Roman Empire was compounded by the spread westwards of barbarian tribes from Eastern Europe, settling areas from which the indigenous populations had been cleared by the spread of the power of Rome, while those populations, notably the Celts, were pushed to the fringes of the former empire. These migrations of barbarian peoples, occuring between the 4th and the 9th centuries, were among the most important changes in European society, but they left no historical record in the accepted sense, and it is necessary to study them at a multi-disciplinary level, drawing on the resources of archaeology, sociology and anthropology. It is the recovery of the customs and beliefs of these populations through such means that forms the common purpose of the studies in this book, for during these centuries the traits and attitudes developed which are at the root of present-day Europe: feudalism, the status level achieved by the merchant class, the beginnings of an ideology that led to the separation of church and state, the demise of slavery as an inefficient mode of production, the origin of national identities, and so forth.
