Henry and Eleanor
When William the Conqueror died in 1087 AD, he left the throne of England to his sons William II and then Henry, and Henry left it to his daughter Matilda. The two Theophanos had just ruled Germany and the Roman Empire, and Matilda of Canossa was ruling Italy, after all. But when Henry died in 1135, his nephew Stephen of Blois grabbed the throne and wouldn't let Queen Matilda rule. Like Anna Comnena in Byzantium about the same time, Matilda fought Stephen for years, but she couldn't get into power.
Eleanor of Aquitaine
But when Stephen died, in 1154, Matilda's son Henry II and his wife Eleanor of Aquitaine took over England (and Normandy, and Aquitaine which belonged to Eleanor, so altogether it was about half of modern France as well). Henry was a strong king. He spent time organizing England, as well as fighting against the French, and against Eleanor, who led a rebellion against Henry to try to get control of Aquitaine for herself.
In Henry's arguments with the Church about whether the Church or
the king was to be more powerful, some of Henry's men murdered St.
Thomas a Becket, the archbishop of Canterbury, in his own church (in
Henry had four sons: Henry, Richard, Geoffrey and John. Henry, the oldest, died (of dysentery) before his father, and so when Henry died Richard became king of England. One of his first acts was to encourage violence against Jewish citizens in England. Richard went on the Third Crusade, which was not very successful. While he was away, Richard left his youngest brother John in charge of England (because Geoffrey had also died, possibly in a tournament). John had to collect a lot of tax money from the English people to pay for the Crusade. And then when Richard the Lionhearted was captured by the Holy Roman Emperor in Germany, John and Eleanor had to raise a huge amount of ransom money with more taxes, largely from taxing monasteries. So John became very unpopular, at least with the land-owners and church officials who were paying the taxes.
In the Robin Hood stories, King John is the bad king who oppresses the poor and chases Robin Hood, and King Richard is the good king who comes back from his travels and pardons Robin Hood. Robin Hood probably never really existed, and the taxes really fell not on the poor but on richer people who had money. But the kings were real.
Learn by doing: hold a tournament
More about King John and the Magna Carta
More about the Third Crusade
More about Eleanor of Aquitaine
King John and the Magna Carta