Piers de Gaveston was a Gascon knight who served in Edward I's army. Although a commoner by birth, he managed to get into Edward's good graces in battle and was appointed "pueri in custodia" to Prince Edward. This rise in status didn't help to humble him out of his naturally cocky attitude.
Apparently, mild-mannered Prince Edward found him pretty enough not to care about his big mouth, and they became close friends. Very close *ahem*. This annoyed Edward, Sr. a bit, and Piers was thus labeled "corruptor of his youth" and banished, along with Prince Edward, for six months. It was a pretty harsh sentence for such a minor incident, but hey, dad wanted grandkids someday, you know? Besides, they also made the mistake of getting caught red-handed by Edward Longshanks' favorite minister and then insulted him on top of it. This additional infraction got Ed, Jr.'s princely allowance taken away.
In 1307, Edward I was thoroughly embroiled in war with the Scots. Prince Edward and Piers were back by this time, and dad was in no mood to deal with them. But love had to rear its ugly head again, and the prince allegedly attempted to grant his pal the region of Pontieu. Not only did this get Piers banished yet again, but according to one chronicler, Walter of Guisborough, got some of young Edward's hair snatched out by dad. Oops.
With Piers gone again, there was nothing better to do at this point but for Prince Edward to join his now seriously ill father in Scotland. Things were getting pretty ugly up there, and England was on the losing end. Then Edward I up and died. Edward, Jr., being the greedy little bugger he was, blew off the battles and ran back home for his coronation and marriage to France's Princess Isabella. Isabella was a quite a looker, and England was overjoyed that Edward II had finally come to his senses and taken such a lovely wife.
Then he had to go and mess things up again. His first actions as king were to put all of his personal buddies in office and fire everyone else, regardless of how good they were at their jobs. As if this weren't bad enough, he brought Piers back into the country, granted him the title "Earl of Cornwall" with all its accompanying benefits, and gave him Isabella's jewels. In the meantime, he continued to ignore Scotland, all of this being much to the dismay of the baronage.
Piers, in spite of having to live out of a suitcase for so long, never lost his arrogance. He made up rude nicknames for his fellow barons and hurled insults at nearly everyone of importance. Naturally, this irritated them. Who did this commoner got lucky think he was, anyway? The barons couldn't take it anymore. They ganged up on Edward, forcing him to exile Piers once again.
In 1309, Piers returned to England, in secret, but unfortunately for him, he couldn't keep his mouth shut for very long. The baronage, suffering from inner turmoil on top of the war, ignored him until he started back to his old tricks. It was time to put an end to the uproar created by this upstart.
In 1310, the barons forced the king, through threats of deposing him, to appoint a group of twelve men "by whose judgement and decree conditions should be reformed and ameliorated." These men were the "Ordainers", and they didn't like Piers much, either. Edward knew they were after his friend.
Then Edward had a brainstorm. "Hey, there's a war out there. Let's leave these guys to their boring old reformation and you and I will go do battle in the Highlands!" And off they went with several other earls.
The Ordainers weren't tickled. They called Edward back to England and imposed a few extra oaths on him. They even ordered him to fire his buddies. This was too much for poor young Eddie and he had a rare temper tantrum. He flatly refused to comply and even passed an order for Piers to return.
Piers never made it back. Before he had a chance, the barons captured and imprisoned him. Arguments ensued on just what to do with the shameless brat. They decided that, in order to preserve the "honor" bestowed upon Piers by the king, he should be beheaded as was befitting a nobleman. In June 1312, Gaveston was taken to Black Hill and executed. Poor Edward.