The beloved of Amadis of Gaul, who called himself Beltenebros
when he retired to the Poor Rock. (Amadis de Gaul, ii. 6.)
Queen Elizabeth is sometimes called the “peerless Oriana,” especially in the madrigals entitled the Triumphs of Oriana (1601).
The nurseling of a lioness, with whom Esplandian, son of Oriana and
Amadis of Gaul, fell in love, and for whom he underwent all his perils
and exploits. She is represented as the fairest, gentlest, and most
faithful of womankind.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894