Papal relations with monarchs in the later eleventh and twelfth centuries have often been characterized as ‘feudal’, as indicative of some sort of papal dominium mundi, or as an effort to advance papal ‘empire’ over the kingdoms of Christendom. More recent scholarship has drawn a distinction between ‘protection’ and ‘feudal’ relationships with kings. However, the supposed distinction between the papacy's temporal overlordship of rulers and its spiritual protection may have obscured more than it has revealed. It was only after the disputes over lay investiture of bishops in the period 1078–1122 that a distinctive protective relationship began to emerge. Previously, rulers had been willing to ‘accept their kingdom from the pope's hand’ or to participate in ceremonies of investiture. In the twelfth century these relationships became more codified and any suggestion that the papacy actually gave kingdoms to kings faded. Thus, the nature of papal ‘empire’ – or, at least, temporal authority over kings – changed markedly during this period.