The beginning of the new millennium saw the rise of what UNESCO called a ”new legacy” of ”digital heritage” and we have since witnessed tremendous efforts to build the archives to contain and profit from that legacy. It is, however, not an easy task to describe such a legacy and its archives. What is an archive? What is cultural heritage? How does one inherit culture? And what difference does it make if the archive is digital or not? This dissertation aims to explore the above questions, not to answer them individually, but to ask concerning the digital cultural heritage archive by tracing certain imaginaries relating to the archive, its technical foundation and instantiation and its political and academic strategies. These imaginaries are described as springing form an archival promise – a promise of what can be attained with regard to knowledge and social organisation if only the archive were to achieve its fullness. The various imaginaries are conceptualised as the promise of archival and political pleroma: an archival plenitude where everything is archived and the archival object reveals itself immediately and a political fulfilment, where society becomes identical with itself and there can be no two respectable and antagonistic opinions. The archival promise is argued to open various strategic domains in ways that require critical scrutiny to break free of the empty operations of pleroma.