The title of Prince of Wales was instituted in 1307 by King Edward I, when he invested his eldest son, Edward, as the first English Prince of Wales, at Lincoln. The traditional ostrich feather badge and the motto Ich dien ( I serve) were adopted by Edward, the Black Prince after the battle of Crecy, they were previously believed to have belonged to the blind King John of Bohemia, who died in the battle.
Cap of Maintenance - Wikipedia, the free encyclopedia. Shield, helm and crest of Edward, the Black Prince (d. 1376) from his tomb in Canterbury Cathedral. Between the lion crest and the helm is a Cap of Maintenance, now almost entirely decayed