Macpherson's interest in the past had been firmly established in his poetry of the late 1750s and early 1760s. In The Highlander (1758) and the Ossianic Collections of the Fragments (1760), Fingal (1761/2) and Temora (1763), Macpherson did more than simply use the past as a source for his stories. Instead, primary sources from the past (both written and from the oral tradition) were used by Macpherson to create his historical narratives that demonstrated his engagement with the past in ways that were thoroughly modern and influenced by the Enlightenment intellectual circles in which he moved. While rooting these poetic forms in primary source evidence was key, Macpherson also used these narratives of the past to articulate his own version of stadial history – the notion that history could be delineated into distinct stages, determined by mode of subsistence, that led human societies from the ‘savagery’ of ancient times to the ‘civilisation’ of the modern era. In his poetry, Macpherson made the argument that the early history of the Highlands laid the foundation for later developments in the region, while also demonstrating how Highlanders were part of a broader civilisation across the British Isles from which contemporary understandings of Britishness were beginning to emerge in the mid-eighteenth century. Using poetry in this way, to create a narrative understanding of the past, demonstrated the essential mimetic qualities of poetic form and echoed the recent claims of Adam Smith regarding poetry as the ideal form of history writing.

These concerns with the past then translated into Macpherson's formal prose historical writing of the early 1770s. Building on his Enlightenment roots in Edinburgh (especially the lectures of Hugh Blair) and the intellectual circles he moved in following his move to London in 1766 (including historians Alexander Dow and the great David Hume), Macpherson wrote about a distant Celtic past and a recent British one using similar historiographical strategies. In his history writing, Macpherson developed his use of source material, explicitly engaging with extensive primary sources from the past and framing them with the scholarly scaffolding of footnotes. Macpherson echoed Hume's injunction that history writing should both amuse and instruct, placing an emphasis on history's didactic qualities in his later writings.