Thomas Becket was killed in his own cathedral in December 1170 by four knights who understood themselves to be acting on the king's wishes, and the cult was immediate. Miracles were reported within days, he was canonised in 1173, and Henry II walked to Canterbury barefoot in 1174 to be scourged by the monks at the tomb. In 1220 the remains were translated into a jewelled shrine behind the high altar, and the anniversary of that translation became the occasion of a jubilee every fifty years, which drew crowds far larger than the ordinary feast.
The pilgrimage generated a whole material culture. Canterbury sold lead ampullae containing water said to be tinctured with a trace of the martyr's blood, and pilgrim badges showing the head of the saint, and thousands of these survive because they were thrown into rivers on the way home. The stone steps to the shrine were worn into hollows by knees.
Henry VIII ended it deliberately and thoroughly. In 1538 the shrine was destroyed and its jewels and gold carted away, Becket was formally denounced as a rebel rather than a saint, his name was ordered struck from service books and his images removed, and a proclamation summoned him to answer charges, so that a man dead three and a half centuries was tried in absentia and condemned. The bones disappeared and have never been located.
What survives is the space. The Trinity Chapel is empty where the shrine stood, marked now by a single candle on the floor, and the Martyrdom, the corner of the transept where he was killed, is the other point pilgrims go to. The destination of this road is an absence, and it is presented as one.