Edward II was, by the standards of the fourteenth century, an extremely unconventional king. As I wrote in my previous post on his character and hobbies, he enjoyed the company of peasants - eating dinner with carpenters and going swimming with a large group of 'common people', to name just two examples - and loved digging, thatching, rowing and numerous other activities considered incompatible with royal dignity.
With this in mind, plus the disasters of his reign and his general ineptness at ruling, it's hardly surprising that many of his contemporaries wondered if he really was royal. Rumours that he was a changeling were widespread during his reign, and matters came to a head in 1318 with the appearance of John of Powderham.
John, also known as John Deydras or Drydas, was (according to contemporary chronicles) the son of a tanner. He somehow gained access to the royal palace of Beaumont in Oxford, and claimed that "he was the true heir of the realm, as the son of the illustrious King Edward, who had long been dead. He declared that my Lord Edward was not of the blood royal, nor had any right to the realm, which he offered to prove by combat with him." (Lanercost Chronicle)
John's story was that as a young child he had been attacked and mauled by a sow in one of the royal residences, and had lost an ear. His nurse was far too terrified to admit this to the king, so substituted a carter's son for the royal child. John, who apparently bore a close resemblance to the king, was indeed missing an ear, and claimed that he, the rightful king of England, had been brought up by the carter while the peasant boy ascended the throne.
John was taken before Edward during the Northampton Parliament of 1318. Edward, who for all his faults was not lacking a sense of humour, greeted him with the words "Welcome, my brother". Edward in fact seems to have taken the whole affair as a huge joke and wanted to make John a court jester, but he was put on trial for sedition anyway, apparently at the request of some of Edward's barons. Finally, John admitted that his story was untrue, but he had been inspired to his actions by the Devil appearing to him in the form of a cat. In true medieval fashion, the 'rightful king of England' was hanged, with his cat alongside him.
Although Edward evidently found all this amusing, Queen Isabella was said to be "troubled beyond measure" by the appearance of John. Early in the twentieth century, Professor Hilda Johnstone wondered if this humiliating episode had sown seeds of doubt in Isabella's mind and ultimately led her along the path that ended with Edward's deposition in 1327. However, in her recent biography of Isabella, Alison Weir points out that there is no evidence that Isabella believed the story, and also that she was probably emotionally vulnerable after childbirth (their third child Eleanor had been born only a few weeks earlier). I believe that Weir's interpretation is the correct one.
It's easy to understand Isabella's concern - as the daughter of two sovereigns, Philippe IV of France and Jeanne, Queen of Navarre in her own right, she would have grown up with a strong belief in the power and dignity of royalty. I can imagine that Edward's love of 'peasant things' was incomprehensible and shameful to her, and for John of Powderham to publicly proclaim that her husband was not royal, but a carter's son - untrue though it certainly was - must have been profoundly humiliating.
As for Edward himself, his unconventionality and individuality are probably the most striking things about him. He was a man out of his time, a man who would have been much better suited to living in a later century, when his preferred activities (not to mention his love for men) would not have been so harshly judged, when a king with the 'common touch' would have been welcomed, not condemned. John of Powderham's story, a nine days' wonder in 1318, demonstrates how Edward and his unconventional behaviour were perceived by many of his contemporaries - with horror and disbelief.