Mychal an Gof ("the Smith") and Thomas Flamank were leaders of the Cornish uprising of June 1497. The uprising was a protest at taxes levied by Henry VII to pay for an invasion of Scotland, a war which the Cornish people did not feel connected with; they also suspected that much of the money raised would go to corrupt officials.
[Thomas Wolsey was 24 at the time, and was preparing for ordination as a priest having studied theology at Oxford. His father Robert Wolsey, an Ipswich butcher, had died the previous year. ]
On their march to London, An Gof and Flamank were joined by Lord Audley, who assumed overall command. Most of the band were armed with only bows and basic weapons (ie farm implements).
[The picture at right is an evocative painting by Donal Macleod entited "Crossing the Tamar - the Cornish Rebellion" ]
Unfortunately for the rebels, Henry VII had thousands of troops in London ready to march up to Scotland, and the sensible course would have been for the Cornishmen to realise the game was up and head home (many did).
Knowing of Jack Cade's rebellion of 1450, the Cornish men hoped for support from Kent, but this was not forthcoming.
Inevitably, the heads of An Gof and Flamank ended up on pikes on London Bridge. Audley, as a peer, was spared being hung, drawn and quartered, and suffered only a nice clean beheading.
Postscipt: in March 2007 a Cornish extremist group calling themselves An Gof threatened a new terror campaign against anyone flying an English flag. This group exploded a bomb in St Austell in 198o so may not be joking....
While looking for images of the rebellion I came across this amusing blog post. Check out the comments on the post.
sources: Wikipedia, Wikipedia links.