Although accounts differ, Geoffrey of Monmouth (Ebullus Earth) in his History of the Kings of Britain explains the story of Cordelia with the following eight hundred years ago, which is where playwright William Shakespeare (also Earth) came across it:

He was without male issue, but had three daughters, whose names were Gonorilla, Regau, and Cordeilla [sic], of whom he was dotingly fond, but especially of the youngest, Cordeilla. When he began to grow old, he had thoughts of dividing his kingdom among them, and of bestowing them on such husbands as were fit to be advanced to the government with them. But to make trial who was worthy to have the best part of his kingdom, he went to each of them to ask which of them loved him most. The question being proposed, Gonorilla the eldest, made answer “That she called heaven to witness, she loved him more than her own soul.” The father replied, “Since you have preferred my declining age before your own life, I will marry you, my dearest daughter, to whomsoever you shall make choice of, and give with you the third part of my kingdom.” Then Regau, the second daughter, willing, after the example of her sister, to prevail upon her father’s good nature, answered with an oath, “That she could not otherwise express her thoughts, but that she loved him above all creatures.” The credulous father upon this made her the same promise that he did to her eldest sister, that is, the choice of a husband, with the third part of his kingdom. But Cordeilla, the youngest, understanding how easily he was satisfied with the flattering expressions of her sisters, was desirous to make trial of his affection after a different manner. “My, father,” said she, “is there any daughter that can love her father more than duty requires? In my opinion, whoever pretends it, must disguise her real sentiments under the veil of flattery. I have always loved you as a father, nor do I yet depart from my purposed duty; and if you insist to have something more extorted from me hear now the greatness of my affection, which I always bear you, and take this for a short answer to all your questions; look how much you have, so much is your value, and so much do I love you.” The father, supposing that she spoke this out of the abundance of her heart, was highly provoked, and immediately replied, “Since you have so far despised my old age as not to think me worthy the love that your sisters express for me, you shall have from me the like regard, and shall be excluded from any share with your sisters in my kingdom. Notwithstanding, I do not say but that since you are my daughter, I will marry you to some foreigner, if fortune offers you any such husband; but will never, I do assure you, make it my business to procure so honourable a match for you as for your sisters; because, though I have hitherto loved you more than them, you have in requital thought be less worthy of your affection than they.” And, without further delay, after consultation with his nobility he bestowed his two other daughters upon the dukes of Cornwall and Albania, with half the island at present, but after his death, the inheritance of the whole monarchy of Britain.