E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Prince of Wales (The).
This title arose thus: When Edward I. subdued Wales, he promised the Welsh, if they would lay down their arms, that he would give them a native prince. His queen having given birth to a son in Wales, the new-born child was entitled Edward, Prince of Wales; and ever since then the eldest son of the British sovereign has retained the title.
Prince of Wales Dragoon Guards. The 3rd Dragoon Guards.