E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
The house of Este had for their armorial bearing a white eagle on an azure shield. Rinaldo, in Jerusalem Delivered, adopted this device; and Ariosto, in his Orlando Furioso, gives it both to Mandricardo and Rogero, adding that it was borne by Trojan Hector. As the Dukes of Brunswick are a branch of the house of Este, our Queen is a descendant of the same noble family.
DEste was the surname adopted by the children of the Duke of Sussex and Lady Augusta Murray.