Thanks to a gift from Pope Francis to King Charles III, two pieces of the true cross on which Jesus was crucified will lead the reigning monarch of the United Kingdom’s coronation procession May 6.

The precious relics have been inlaid into the “Cross of Wales,” which will head Charles’ procession into Westminster Abbey, where he will be officially crowned.

Many will be watching the ceremony to witness the pomp and circumstance still found in the official functions of the British royalty. Yet, at the forefront of all that spectacle, the simple metallic cross, inlaid with relics of the wood of the true cross, testify to a lesser-known, deeply Christian aspect of the British royal tradition.

Among his many titles and symbolic responsibilities as king of England, Charles is also the supreme governor of the Church of England, which broke away from the Catholic Church in 1534 under King Henry VIII.

Given that many consider the pieces of the cross among the most precious relics in all of Christendom, the pope’s gift is being seen as an incredible ecumenical sign of goodwill.

The U.K.’s ambassador to the Holy See, Chris Trott, expressed his gratitude to the pope in a tweet, saying: “We are deeply moved and grateful to Pope Francis for this extraordinary gift. Reflecting the strength of the [Vatican-U.K.] relationship that developed over the course of the reign of Her Late Majesty Queen Elizabeth, who met 5 Popes!”

Given that the relationship between the British crown and the Catholic Church has been rocky in ages past, Charles’ decision to place the papal gift at the forefront of his coronation ceremonies is significant.

The Cross of Wales is made of Welsh slate, wood, and silver. On it are inscribed the Welsh words of St. David, patron saint of Wales: “Be joyful. Keep the faith. Do the little things.” At the center, arranged into a tiny cross are the precious shards of Christ’s cross.

Relics of the true cross have long been treasured by Christians around the world. According to legend, St. Helena, the mother of Constantine, miraculously discovered the cross in 326. Pieces of the cross were taken back to Rome and Constantinople. From there those pieces were further divided and dispersed to other shrines and holy sites.

There are historical references of Christians venerating the true cross throughout the centuries across Europe, the Mediterranean, and later the rest of the world.

According to historians of the Crusades, the true cross was regularly carried into battle by the armies of the Crusader kingdom of Jerusalem.

Today, there are relics venerated around the world all believed to be pieces of the true cross.

In Rome’s Basilica of the Holy Cross in Jerusalem there are fragments believed to be from portions of the true cross brought to the city by St. Helena. Among the relics housed in this basilica is a piece of wood known as the “Titulus Crucis” (title of the cross), on which is written in Greek, Latin, and Hebrew: “Jesus the Nazarene King of the Jews.”

In the U.S., there are relics believed to be pieces of the true cross in California, Connecticut, Florida, Indiana, Texas, Missouri, New York, and Ohio.

As the former Prince of Wales, Charles entrusted the pope’s gift to the Church in Wales, a branch of the Church of England.

According to an official April 19 statement by the Church in Wales, the cross will be made available for veneration to both the Anglican and Catholic churches in Wales.

Joining in the Church in Wales’ statement, Archbishop Mark O’Toole of the Catholic Archdiocese of Cardiff and Diocese of Menevia expressed his gratitude and joy over the precious gift.

“With a sense of deep joy we embrace this cross, kindly given by King Charles, and containing a relic of the true cross, generously gifted by the Holy See. It is not only a sign of the deep Christian roots of our nation but will, I am sure, encourage us all to model our lives on the love given by our Savior, Jesus Christ. We look forward to honoring it, not only in the various celebrations that are planned but also in the dignified setting in which it will find a permanent home,” O’Toole said.