An idea can hold a people together and sustain it. A shared political memory and an inspiring history of the Franks as the centre of the world, such as is presented in the Annales regni francorum and disseminated from the royal court may have done much to buttress Carolingian rule. Recalled past experience and shared images of the past are the kinds of memories that have special importance for the constitution of social groups. Within these, the creation of accounts of past events that draw on memory but select from it in distinctive ways that become accepted, and thereafter are shared by a group, is the process of constructing the past. The Franks' historical writing, as we have seen, served to reinforce the Franks' own sense of place in the framework of history and in relation to the past. Much has already been written about the role of the past in the political and cultural consciousness of the Franks. Their interest in the Roman imperial and Christian past is clear from the surviving manuscripts and library catalogues, but it is vital to set this beside the evidence for contemporary history provided by the annals, for it is in the image of the immediate past that the Carolingian political ideology is presented at its most fervent, backed up by telling circumstantial detail and stories of success. The exegesis of past events was provided as a way of indicating the proper political positions of the present and the shaping of the future.