Definition of "Constance"

And forth she sailed the ocean salt and rude. / O Constance, full of sweet solicitude, / O Emperor's daughter of a mighty realm, / He that is Lord of Fortune guide thy helm!

1951, Geoffrey Chaucer, “The Man of the Law's Tale”, in Nevill Coghill, transl., The Canterbury Tales: Translated into Modern English (Penguin Classics), Penguin Books, published 1977

My name is Constance; I was Geffrey's wife; / Young Arthur is my son, and he is lost: / I am not mad:—I would to heaven I were!

c. 1596 (date written), William Shakespeare, “The Life and Death of King Iohn”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act III, (please specify the scene number in lowercase Roman numerals)]