2Loomis, Laura H. A. "Geoffrey of Monmouth and Stonehenge." PMLA 45.2 (1930): 400.
The story of the Irish origin of Stonehenge was repeated a generation after Geoffrey by Giraldus Cambrensis in his Topographia Hibernica (1187). Loomis adds, "Chroniclers repeated the tale and successive generations believed, to borrow Spenser's wording, that they could 'Th'eternall marks of treason... at Stonheng vew.' (F. Q.,II, x, 66)." The earliest known mention of Stonehenge was by Henry of Huntingdon in 1130: ""Stanenges, where the stones of wonderful size have been erected after the manner of doorways, so that doorway appears to have been raised upon doorway; and no one can conceive how such great stones have been so raised aloft, or why they were built there." Thomas Arnold (ed.) Henrici Archidiaconi Huntendunensis Historia Anglorum. Rolls series, London: Longman & Trübner, 1879. 11-12.