Not the least of the unusual revelations that have come from the wonderfully preserved ninth-century Norwegian ship burials at Oseberg and Gokstad, is the fact that both had been later broken into-by interlopers who defaced the ship, damaged the grave goods and pulled out and dispersed the bones of the deceased. These 'mound-breakers' helpfully left spades and stretchers in place, and through the application of some highly ingenious dendrochronology our authors have been able to date the break-ins with some precision. Mound-breaking, it seems, took place during the domination of Norway by Harald Bluetooth in the tenth century as part of an extensive campaign which included subduing local monuments as well as converting Scandinavians to Christianity. The old mounds retained such power in the landscape that it was worth desecrating them and disinterring their occupants a century after their burial.