What is the name of the 12th-century archbishop of Canterbury killed in 1170, later made a saint?

The story behind the answer

He was the archbishop of Canterbury who clashed fiercely with King Henry II over the independence of the Church. On 29 December 1170, four knights—thinking they were fulfilling the king’s will—murdered him in Canterbury Cathedral. Canonized just three years later, his shrine became one of Europe’s most famous pilgrimage sites, later immortalized in Chaucer’s Canterbury Tales.

The alternatives don’t match: Anselm died in 1109, Stephen Langton was a 13th-century archbishop linked to Magna Carta, and Thomas Cranmer was a 16th-century Reformation leader executed under Mary I.