In 1173-4 Henry was faced by a revolt by his wife, children and many of his leading barons. 1183 to his death in 1189 were years where Henry was increasingly beset by his enemies until at the age of 56 he died, faced with the treachery and disloyalty of his family.
The Great Revolt, 1173-4
Henry the Young King slipped away from his father's side at Chinon and fled to Louis in Paris. Louis at once recognised him as the rightful king. Eleanor and her teenage sons, Richard and Geoffrey also declared for the young Henry, and rode to Paris to join him. Barons across the empire rose in revolt against Henry's firm control; in Britain, the Earls of Chester, Leicester, Derby and Norfolk were joined by William the Lion of Scotland.
All were outdone by Henry's speed, his small but effective hardened army of mercenaries, and the support from his royal officials such as Richard de Lucy, Justiciar of England. By August 1174, Henry had subdued the English barons and chased away a humiliated Louis from the walls of Rouen.
At the Treaty of Montlouis, Henry was not vindictive; we tried to solve the problems. Henry the Young King was given a pension to maintain himself; Geoffrey given Brittany and Richard Aquitaine. But Eleanor was to remain in prison for 10 years. William the Lion had to accept Scotland back as a fief of the English Crown - just like an English Earl.
New Technology and the seige train
One of the reasons Henry was so successful was that unlike the rebels he had an effective siege train. And one of the reasons for this was the Trebuchet, which comes into regular use at this time. The trebuchet, as opposed to the less powerful Mangonel, used a counterweight to generate it's energy rather than torsion. And of course Henry had a team of experts to help him use the technology effectively.
Humiliation and Death
In 1180 Phillip II Augustus came the throne of France. His 43 year reign was to transform the map of France. Phillip was helped and supported by Henry during his early years - but Phillip had no intention of returning the favour, and schemed for Henry's downfall, exploiting the divisions among Henry's sons. In 1182 Henry the Young King died, and in 1186 Geoffrey died. The person who bears the most to blame for Henry's final defeat was Richard, who conspired with Philip and joined in attacks down the Loire in 1188.
Henry simply refused to fight back. Tired, ill and feverish, Phillip dictated terms to Henry near Chinon. Ill though he was, Henry was furious with his son he whispered in Richard's ear ‘May the Lord spare me until I have taken vengeance on you’.
What finished Henry was the news, smugly delivered by Phillip, that his favourite son, John, had joined the revolt against him . Henry died at the age of 56 on 6th July 1189. He had reigned for 34 years and was buried at Fontevraud.