or Isabella (in Orlando Furioso). Daughter of the king of Galicia, in love with Zerbino; but, being a pagan, Zerbino could not marry her. Zerbino induces her to quit her native land, and gives Odorico charge of her. She is wrecked, and Odorico escapes with her to Rocheile. Here Odorico assails her virtue, but is alarmed by a vessel which he sees approaching, and flees. She is kept captive by the crew for nine months, but Orlando slays or hangs all the crew, and Isabella being free, accompanies her rescuer. Her lament at the death of Zerbino is one of the best parts of the poem (book xii.). She retires to a chapel to bury Zerbino, and is there slain by Rodomont.
The colour so called is the yellow of soiled calico. A yellow-dun horse is called in France un cheval isabelle. The tale is attached to Isabel of Austria and Isabel of Castile. It is said that Isabel of Austria, daughter of Philip II., at the siege of Ostend vowed not to change her linen till the place was taken. As the siege lasted three years, we may well suppose that it was somewhat soiled by three years' wear.
“His colour was isabel, a name given in allusion to the whimsical vow
of Isabella Clara Eugenia, Governess of the Netherlands, at the
memorable siege of Ostend, which lasted from 1601 till 1604.” —
Isabel of Castile, we are told, made a vow to the Virgin not to change her linen till Granada fell into her hands; but this siege lasted longer than ladies are wont to wear their body-linen.
“Bright-Sun was mounted on a black horse, that of Felix was a grey,
Chery's was white as milk, and the princess's an isabelle.” —
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894