I feel I have to jump to John's defence. He was certainly no great king, but he was nowhere near as bad as he has been portrayed. No - the villain of the era was actually his older brother Richard - yes, the Lionheart. In an effort by the Victorians to provide figureheads for the Empire, Richard became transformed into a just and kindly king, dealing fairly with all his subjects and almost carrying a permanent halo. In fact, he was one of the worst kings England ever had. He could speak little or no English and spent less than six months of his 10-year reign actually in England. Even so, he managed to almost bankrupt the country three times over to finance his failed crusades in the Holy Lands and to pay the ransoms on the several occasions when he got himself captured.
Remember when Richard Greene was Robin Hood? And how often King Richard visited the Greenwood to talk to Robin, and everyone went down on one knee with bowed heads? Actually, they would more likely have spat at him, as it was Richard's fault that a large set of despots had been left to 'run' the country.
John had many faults, but not, I'd suggest, as many as his older brother. And at least he gave us (under protest) Magna Carta.