The cross is arguably the most iconic of all icons: an instantly recognisable symbol that is infinitely replicable, and which has spread across the world. We wear it on jewellery; we recreate it on our bodies when we make the sign of the cross; we hang it in our churches and even build our churches in its shape. And yet we rarely think, except perhaps on Good Friday, about the actual, physical cross on which Jesus died.

This is strange, since, as Evelyn Waugh expressed in his novel exploring the life of Empress Helena, ‘what is different about Christianity is that it identifies the mystery of God with a set of prosaic happenings in a specific place.’ God became a human being, at a particular time, in a specific place, and lived a human life, and died a human death. The cross is the ultimate expression of this specificity: a real physical object which not only touched Jesus’ body, but which was an instrument in his death, and therefore in our salvation. Empress Helena, the mother of Constantine the Great, is said to have discovered the True Cross when travelling in the Holy Land in the Fourth Century, sparking centuries of veneration of fragments and splinters of wood, as they spread across Europe and the world.

Christians in the reformed tradition can sometimes be sneering about the existence of relics of the True Cross – this goes back to the Reformation scepticism of relics in general, and the writing of John Calvin, who estimated that ‘if all the pieces that could be found were collected together, they would make a big ship-load.’ Later estimates have been more conservative, suggesting that the medieval trade in relics was not quite so deceitful as Calvin suspected. The relics which do survive still have considerable power over our collective religious imagination: the Cross of Wales, which was newly commissioned for the Coronation of Charles III contains two fragments of the True Cross, presented by Pope Frances to the new king.

This Sunday, we will celebrate the feast of the Holy Cross with evensong at St Cross Church. Whether or not we believe in the truth of the story of Empress Helena, or in the authenticity of surviving relics, the feast reminds us of the astonishing reality at the heart of our faith: the real human life and real human death of Jesus Christ.