Short answer
The murder of Archbishop Thomas Becket in Canterbury Cathedral on 29 December 1170 was the most dramatic moment in a decade-long power struggle between King Henry II and the Church. Their conflict reveals how medieval kings and popes competed for authority over England's clergy — and the price paid for that competition.
At a glance
- Key stage
- Key Stage 3
- Subject
- History
- Type
- Guide
- For
- Students
- Read time
- 6 min
- Last updated
- 8 October 2026
Where this fits
- Key Stage 3Years 7–9This article
- GCSEYears 10–11
How did Henry II and Thomas Becket come into conflict?
Henry II came to the throne in 1154 determined to restore royal authority after the chaos of King Stephen's reign. One priority was reining in the power of Church courts, which claimed the right to try priests accused of crimes — including serious ones like murder — without any involvement from royal justice. Henry believed this created a dangerous gap in the law: a clergyman who committed a crime could receive a mild Church penalty and escape royal punishment entirely.
In 1162, Henry made his close friend and chancellor Thomas Becket the Archbishop of Canterbury, expecting Becket to support his reforms. He was quickly disappointed. Becket took his new spiritual duties seriously and became a fierce defender of Church independence, reversing the accommodating approach he had shown as chancellor. The two men who had been friends found themselves on opposite sides of a fundamental question: who held ultimate authority in England — the king or the Church?
What were the Constitutions of Clarendon?
In 1164 Henry drew up the Constitutions of Clarendon — a set of sixteen written clauses that tried to define the boundary between royal and Church authority, firmly in the crown's favour.
| Key Clause | What it claimed |
|---|---|
| Clause 3 | Clergy charged with serious crimes to be tried in royal courts after Church courts had heard the case |
| Clause 4 | Archbishops and bishops could not leave England without royal permission |
| Clause 8 | Appeals in Church cases to go no further than the Archbishop — not to the Pope in Rome |
| Clause 12 | Revenues of vacant Church positions to be held by the king |
Becket initially agreed under pressure, then withdrew his agreement and appealed to the Pope. Henry was furious. Becket fled to France for six years rather than face the king's anger. The dispute became an international affair involving the Pope, the French king, and the English nobility.
Why did the quarrel become so bitter?
The conflict between Henry and Becket was personal as well as political. Henry felt betrayed by a man he had trusted and promoted. Becket — once a pragmatic royal servant — had become a principled and, some thought, self-dramatising champion of the Church who seemed to enjoy the role of martyr. Both men were proud and neither found compromise easy.
The historian's approach here matters: we have accounts of the dispute from both royal and Church sources, and each portrays its own side sympathetically. Church writers show Becket as a courageous saint; royal accounts emphasise his stubbornness and ingratitude. Reading these sources alongside each other reveals the contested nature of the conflict rather than a clear moral verdict.
In 1170 Becket returned to England but immediately inflamed matters by excommunicating bishops who had supported Henry. Henry, reportedly furious, made a statement that four of his knights interpreted as a wish to be rid of Becket.
What happened on 29 December 1170?
On the evening of 29 December 1170, four knights — Reginald FitzUrse, Hugh de Morville, William de Tracy, and Richard le Breton — rode to Canterbury Cathedral and confronted Becket. When he refused to lift the excommunications or leave the cathedral, they attacked and killed him at the altar. The murder of an archbishop inside a house of God sent shockwaves across Christendom.
Within three years, Pope Alexander III declared Becket a saint. Canterbury became one of medieval Europe's most important pilgrimage destinations — the journey Chaucer's pilgrims make in The Canterbury Tales nearly two centuries later reflects how central Becket's shrine remained.
Why did Henry II perform public penance?
Henry denied ordering the murder, but he could not escape responsibility for the climate that led to it. In 1174 he walked barefoot to Becket's tomb at Canterbury Cathedral and was flogged by monks as an act of penance. This was not merely personal guilt: it was a calculated political act. By doing penance, Henry acknowledged the Church's moral authority and partially defused a crisis that had threatened to cost him his crown.
What was the historical significance of Becket's murder?
The conflict between Henry and Becket illustrates a central tension in medieval governance: no English king could govern effectively without the Church's cooperation, yet no king was willing to concede that the Church's authority exceeded his own. The murder did not resolve that tension, but it shifted the balance — for a generation at least — towards the Church.
| Before Becket's murder | After Becket's murder |
|---|---|
| King claimed right to try clergy in royal courts | Henry abandoned Clause 3 of the Constitutions of Clarendon |
| Clergy could appeal to Archbishop only, not Rome | Right to appeal to Rome restored |
| Archbishop needed royal permission to travel | Church freedom of movement largely restored |
Becket's case also matters as a source-evaluation exercise. The four principal accounts — written by monks who knew Becket — are almost hagiographic. Weighing their perspective against the silence of Henry's own court, and asking what each author needed to believe, is a model of historical thinking at KS3.
Frequently asked questions
Why did Henry II make Becket Archbishop of Canterbury?
Henry chose Becket because Becket had served him loyally as Lord Chancellor for eight years and understood the king's desire to extend royal authority. Henry expected the same compliance in the Church that Becket had shown at court. The miscalculation was in assuming that the role of Archbishop would not change the man.
Did Henry II order the murder of Thomas Becket?
Henry never admitted ordering the murder, and most historians believe his words — reportedly "Will no one rid me of this troublesome priest?" — were an outburst of anger rather than a direct command. But his role in creating the conditions for the murder, and the fact that the knights were members of his household, meant the responsibility could not be separated from the king.
Why is Thomas Becket important in KS3 history?
Becket's story is significant because it illustrates the power of the medieval Church and the limits of royal authority in the 12th century. It also shows how historical events can be interpreted very differently depending on who wrote the account — a key skill in KS3 and GCSE history source work.
What happened to the four knights who murdered Becket?
Pope Alexander III excommunicated the four knights. They were eventually required to go on crusade to the Holy Land as a form of penance. They were never executed or tried in English courts, partly because Henry could not afford a further confrontation with the Church and partly because proving direct royal orders would have been impossible.
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