The leaders of many of the Scandinavian incursions into western Europe in the ninth century were exiles and quite often members of a royal family or of royal stock who had been expelled from their home countries by more powerful relatives. They tended to use their time as exiles pillaging and extorting wealth, or selling their services as mercenaries, seemingly with the intention to return home one day with sufficient strength to challenge for power. Many of them never did return, but some of them did, with varying degrees of success. This has long been recognised by many historians . Yet despite all the acknowledgments very little has been written about the several attempts by « exiled » members of Danish « royal families » to return to Denmark and seize some power there . This paper will examine perhaps the prime, and certainly the best documented, case of such returns to Denmark: that which took place in 854. In this year some relatives of the Danish king Horik I tried to gain control of the Danish kingdom and a veritable civil war ensued. This provided the opportunity for other « piratical » Scandinavian chieftains who had for years been raiding « the territories of the kingdom of the Franks through places which were accessible to them using their ships » to return quickly to Denmark to join in this struggle for power. In this article what « actually happened » in 854 in Denmark will be explored using the sources we have. Then, by looking both forward and backwards a little, we will consider the context of these events and who the « relatives » of Horik I and the returning « pirates » may have been. Finally, the question of what the consequences of this « civil war » for Denmark itself were, and whether these fights ultimately contributed to, or even spurred, an upsurge in viking raiding « overseas » in western Europe, as has often been claimed, will be addressed.< Réduire