This article investigates the claim found in London, British Library, Burney 357, fol. 12rv, that a count of Leicester called Robert used to recite from memory certain verses found in this manuscript. Revising previous reports that the remark refers to a poem in praise of holy monks by an otherwise unknown poet 'Sygerius Lucanus', it argues for its plausibility by suggesting that it concerns two brief poems of a different character, most notably the Epitaphium Senecae, a poem that evokes the deeds and ideas of the Roman philosopher Seneca. Since the poem was well-known for its associations with Seneca, the note suggests that an earl of Leicester, probably Robert II (1120–68), but perhaps Robert I (1107–18) or Robert III (1168–90), was interested in classical life and thought. The article goes on to offer a critique of the tendency to dismiss the cultural agency of magnates like the Beaumonts in preference for that exercised by the cathedral schools and religious houses. Arguing for a more nuanced approach, it suggests that greater weight ought to be given to evidence such as the remark in Burney 357—evidence which suggests, despite the surviving record’s profound bias in favour of religious persons and institutions, that certain lay magnates helped to promote some of the period’s most striking cultural fashions, not least its surge of interest in Senecan texts and ideas. Other issues treated include the dissemination of Senecan anthologies, Sygerius Lucanus, his poems, their sources, and their gender politics.