The Crusades were a time of conflict and treasure hunting, resulting in valuable artifacts being transported and often lost. Some of the most sought-after relics include John the Baptist's head, the True Cross, the Mandilon of Adessa, and the Crown of Thorns. The head of John the Baptist is coveted by those who hunt for Christian relics, with at least four places claiming to possess it.

The True Cross, said to be a piece of the Cross of Golgotha, has caused trouble throughout history and is likely to be a collection of fake pieces. The Mandilon of Adessa, a mythical treasure with a miraculous image of Jesus Christ's face on it, was worshipped in the Byzantine Empire until the 10th century, when it disappeared. The Crown of Thorns is believed to have been brought to Paris by King Louie in 1239 and is now housed in Notre-Dame Cathedral. Despite being a symbol of Christianity, some of these relics are contested, and their authenticity remains in question.