The triple anniversary in 2020 of Thomas Becket’s birth, death and translation has been an occasion to review and revisit many of the artefacts associated with the saint and his cult in England and across Europe. Many of these are items directly associated with his veneration in churches or in private devotions, but one object which served in neither capacity is an instrument case currently in the collection of the Worshipful Company of Barbers in London. This unusual object has been studied for its fine silver work, and possible royal associations, but little academic attention has so far been paid to the some of the iconography, particularly that of the scene of the murder of Thomas Becket depicted on the back of the box, the side to be worn against the body. In this article, we show how seemingly unusual elements in the iconography draw on particularly Flemish representations of Becket’s murder that, to date, have received little attention in Anglophone scholarship. From this, we discuss this scene and its significance in understanding the role the iconography may have been intended to serve, and the interplay between the decorative schema and what the surgeon thought about his own role with regard to the use of the case and its tools.