[note 2] Gilbert's father was from Thierville in the lordship of Brionne in Normandy, and was either a small landowner or a petty knight.

Around the age of 20, he spent about a year in Paris, but he did not study canon or civil law at the time and his Latin skill always remained somewhat rudimentary.

[8] As Chancellor, Becket enforced the king's traditional sources of revenue that were exacted from all landowners, including churches and bishoprics.

[1] A rift grew between Henry and Becket as the new archbishop resigned his chancellorship and sought to recover and extend the rights of the archbishopric.

Attempts by Henry to influence other bishops against Becket began in Westminster in October 1163, where the King sought approval of the traditional rights of royal government in regard to the church.

[1] This led to the Constitutions of Clarendon, where Becket was officially asked to agree to the King's rights or face political repercussions.

Finally, even Becket expressed willingness to agree to the substance of the Constitutions of Clarendon, but he still refused formally to sign the documents.

Henry summoned Becket to appear before a great council at Northampton Castle on 8 October 1164, to answer allegations of contempt of royal authority and malfeasance in the Chancellor's office.

Becket fought back by threatening excommunication and an interdict against the king and bishops and the kingdom, but Pope Alexander III, though sympathising with him in theory, favoured a more diplomatic approach.

",[14] but according to historian Simon Schama this is incorrect: he accepts the account of the contemporary biographer Edward Grim, writing in Latin, who gives, "What miserable drones and traitors have I nourished and brought up in my household, who let their lord be treated with such shameful contempt by a low-born cleric?

According to accounts by the monk Gervase of Canterbury and eyewitness Edward Grim, the knights placed their weapons under a tree outside the cathedral and hid their armour under cloaks before entering to challenge Becket.

The four knights, wielding drawn swords, ran into the room crying, "Where is Thomas Becket, traitor to the King and country?"

This is part of his account: ...the impious knight... suddenly set upon him and [shaved] off the summit of his crown which the sacred chrism consecrated to God... Then, with another blow received on the head, he remained firm.

But with the third the stricken martyr bent his knees and elbows, offering himself as a living sacrifice, saying in a low voice, "For the name of Jesus and the protection of the church, I am ready to embrace death."

[20] Soon after, the faithful throughout Europe began venerating Becket as a martyr, and on 21 February 1173 – little more than two years after his death – he was canonised by Pope Alexander III in St Peter's Church, Segni.

[21] On 12 July 1174, amidst the Revolt of 1173–74, Henry humbled himself in public penance at Becket's tomb and at St Dunstan's Church, Canterbury, which became a most popular pilgrimage site.

De Morville also held property in Cumbria and this too may have provided a hiding place, as the men prepared for a longer stay in the separate kingdom of Scotland.

Seeking forgiveness, the assassins travelled to Rome, where the Pope ordered them to serve as knights in the Holy Lands for a period of 14 years.

[citation needed] The monks were afraid Becket's body might be stolen, and so his remains were placed beneath the floor of the eastern crypt of the cathedral.

[22] A stone cover over it had two holes where pilgrims could insert their heads and kiss the tomb,[1] as illustrated in the "Miracle Windows" of the Trinity Chapel.

On 7 July 1220, the 50th jubilee year of his death, Becket's remains were moved from his first tomb to a shrine in the recently built Trinity Chapel.

[1] This translation was "one of the great symbolic events in the life of the medieval English Church", attended by King Henry III, the papal legate, the Archbishop of Canterbury Stephen Langton and many dignitaries and magnates secular and ecclesiastical.

The men of Strood had sided with the king in his struggles against the archbishop, and to demonstrate their support had cut off the tail of Becket's horse as he passed through the town.

The first holy image of Becket is thought to be a mosaic icon still visible in Monreale Cathedral in Sicily, created shortly after his death.