With some lines, some fifty stanzas into his epic sentimental fantasy A Faerie Romance (1751 - 1803) made his first mention of Promethea. A character who has since then evolved into a fascinating literary mystery in her own right.

Promethea, a handmaiden "with skin like polished betel-wood" is introduced as one of four handmaidens to the Faerie Queen Titania (a straight crib for A Midsummer Night's Dream, to which it seems Sennet originally intented his own poem as a tribute), but with a dozen or so stanzas seems to have completely taken over both the entire poem and the poet's imagination.