In the summer of 1450 the three counties that lie in the south-eastern corner of England, Kent, Surrey, and Sussex, rebelled, under the leadership of a certain Jack Cade, who called himself Captain of Kent. They complained that the King had bad advisers about him, that the English possessions in France had been lost by treachery, and that the taxes were unbearably heavy. Who Jack Cade himself was is not known for certain. He gave out that he belonged to the noble family of Mortimer. It should be observed that the leaders of Wat Tyler's rebellion did not pretend to be anything but workmen, whereas the chief of this pretended that he was a man of high birth. According to some accounts he was an Irishman, who had fought in France against the English, but had afterwards come over to this country. He led his men to Blackheath, where they encamped. It is said that there was a great multitude of them, and that they were well disciplined and well armed. The King or rather his ministers, for Henry himself had very little spirit, and was for the best part led by others, raised an army of 15,000 men and marched against the rebels. Cade did not feel himself able to meet so strong a force, and retreated southward. The King was preparing to pursue him, but his wife, Margaret of Anjou, is said to have been afraid that he might meet with some injury, and to have prevailed upon him to stay behind himself, and send two of his generals, Sir Humphrey Stafford and his brother William, to attack them. Cade had been afraid to resist the King. Perhaps he knew that his followers would not back him up in doing so. But it was a different thing when he had to do with a couple of knights. At Sevenoaks he turned upon his pursuers and defeated them, killing both their leaders. After winning this victory he marched northward again, and encamped once more on Blackheath. And now the city of London came over to him. The Common Council voted that the gates of the town should be opened to him, and he marched his troops across London Bridge, and took possession. This he did by striking his sword on "London Stone" and crying out at the same time, "Now is Mortimer Lord of London."

The King, still under the influence of his wife, who did not behave with anything like the courage that she afterwards showed, had fled to Kenilworth Castle in Warwickshire, and it seemed as if the rebellion were likely to succeed. For a time Cade was able to keep his men in good order. They remained in the city during the day, but without plundering the property of the citizens or doing any injury to man, woman, or child. Every night their leader took them across the bridge to Southwark, which is on the other side of the river. But this happy state of things did not last very long. Cade seized the Treasurer, Lord Saye and Sele, who had made himself very unpopular, and brought him before the Lord Mayor. The Lord Mayor condemned him, and he was executed in Cheapside. Another victim was Lord Saye and Sele's son-in-law, Crowmer, who was Sheriff of Kent. The citizens of London did not approve of these proceedings, and putting themselves under the command of one Matthew Gough, who had the reputation of being a skilful soldier, tried to prevent Cade and his followers from coming over the bridge from Southwark into London. A fierce fight took place. The Londoners, who had posted themselves at the southern end of the bridge, were driven back to the middle, where there was a drawbridge. Matthew Gough was killed in the battle. But though the rebels had the best of the fighting, Cade did not feel strong enough to enter London again, and remained on the south side of the river.

And now the King's counsellors thought that they might be disposed to listen to offers of peace. The Archbishop of Canterbury and the Bishop of were sent to treat with them. They found Cade dressed in a splendid suit of gilded armour which had belonged to Sir Humphrey Stafford. The Archbishop afterwards spoke of him as having been "sober in talk and wise in reasoning, though arrogant in heart and stiff in opinion." The Archbishop promised that the things complained of should be set right, and that no man should be punished for having taken part in the rebellion. On hearing this Cade's followers dispersed to their homes. They had got, they thought, what they wanted, and now the sooner they went back to their own business the better. But Cade was not satisfied. Perhaps he was afraid that, having been the leader of the whole affair, he would be excepted from the pardon. Perhaps, having had a taste of power, he was not willing to give it up. As his own people had left him, he is said to have provided himself with a new force by breaking open the gaols and setting free the prisoners. But this was a kind of army which did not hold together very long. With some of his followers Cade made his way to Rochester, whither he sent the plunder which he had collected. About this plunder they quarrelled, and Cade, leaving his companions, tried to make his escape alone. By this time a price of £1000 had been set upon his head. At Heathfield, a village in the Weald of Sussex, he was overtaken by Alexander Iden, who had been made Sheriff of Kent, and mortally wounded. Iden would have taken him to London, but he died on the way.