Anyone wishing to unravel the history of the relationship between Byzantium and Armenia from late antiquity into the eleventh century has to confront a series of historical and historiographical challenges. The most immediate, and intractable, of these is one of definition: what does ‘Armenia’ mean? Although Armenia is used to express a territorial entity in contemporary texts, both Armenian and non-Armenian in origin, its precise meaning varies according to the date and the context in which it is used. Far from finding a single, stable definition of Armenia, one discovers multiple ‘Armenias’. Thus a seventh-century Armenian geographical compilation depicts ‘Great Armenia’ as comprising not only regions currently recognised as Armenian but also those with historic associations. Successive provinces of Armenia were imposed and superimposed by external powers, each with a particular scope. The kingdom of Armenia, re-established in 884, bore little relation to its Arsacid precursor and increasingly represented only the Bagratuni kingdom centred on Ani, excluding rival kingdoms in Vaspurakan, Siwnik‘ and elsewhere.