Four knights loyal to King Henry II were responsible for the murder of Archbishop Thomas Becket inside Canterbury Cathedral on December 29, 1170. The assailants—Reginald Fitzurse, Hugh de Morville, William de Tracy, and Richard le Breton—carried out the attack near the altar, an act that shocked medieval Europe due to the Church’s dominant social and political role at the time.

While the knights are the most commonly cited perpetrators, historical accounts indicate that others were involved in both planning and executing the killing. The group was hosted by Ranulf de Broc at his castle in Saltwood, near Hythe, Kent. De Broc played a leading role in orchestrating the murder and traveled with the knights toward Canterbury. Accompanying them was his chaplain, Hugh de Horsea, along with armed retainers known as serjants—all of whom opposed Becket. During the assault, Hugh de Horsea is reported to have actively participated, while de Broc remained stationed outside the cathedral with his forces.

Following the killing, the four knights fled first to Scotland and subsequently to de Morville’s stronghold at Knaresborough Castle in North Yorkshire. Their refuge lasted until news surfaced that Pope Alexander III had excommunicated them on March 23, 1171, Maundy Thursday. This ecclesiastical condemnation effectively ostracized the knights from church protection and secular law, intensifying the gravity of their crime.

In response to the excommunication, the knights traveled to Rome to seek the Pope’s judgment. Alexander III condemned them to serve for 14 years as crusaders in the Holy Land. Following their military service, they were to retire to a hermitic life in a secluded region near Antioch, in present-day Turkey.

Historical records do not confirm the exact fates of the four knights following these sentences, but it is generally believed that none survived beyond approximately 1173. Hugh de Horsea, derided post-murder as Mauclerc, or “Evil Cleric,” disappears from contemporary accounts soon after the event. Ranulf de Broc, by contrast, lived until about 1179, married, and left behind five daughters.

The assassination of Thomas Becket resonated deeply throughout Christendom, underscoring the fraught relationship between secular rulers and ecclesiastical authority during the 12th century. The violent breach of sanctuary within Canterbury Cathedral remains a pivotal event reflecting the era’s complex interplay of loyalty, power, and penance.