Edward I was the son of King Henry III of England and succeeded his father on the throne at the age of 33 in 1272, though he had had a lot of power beforehand as Henry had been a weak ruler. He was known as the "Hammer of the Scots" because he spent so much time trying to conquer Scotland. He also subjugated Wales and had many castles built there as English strongholds. He summoned several Parliaments, setting a precedent for English government, and when his first wife Eleanor died on a journey to Scotland in 1290, he was so grief-stricken that he erected a memorial cross in each place where her body stayed overnight on the trip back to London. (He did marry again, about nine years later.) At the age of 68 he was still fighting around the Scottish border and died of dysentery in 1307 on one of those campaigns. He was succeeded on the throne by his son Edward II.

Don't ask me why he's Edward I when he reigned after Edward the Confessor and a few other kings named Edward. (Wertperch tells me it's because the numbering of kings started after the Norman Conquest. That makes sense, I guess.)