Over the centuries, the head of John the Baptist has ranked high on the list of the most sought-after relics in Christianity. The Jewish preacher and prophet, celebrated as one of the earliest Christian saints, is believed to have paved the way for his distant cousin, Jesus, whom John famously baptized in the Jordan River.

According to all four canonical gospels of the New Testament, as well as the account of the Jewish historian Josephus, John the Baptist was killed on the orders of a local ruler sometime before Jesus’ crucifixion. The gospels claim the king had him beheaded, and his head put on a platter. But no one gives any clue about where John the Baptist’s head—or the rest of his body—ended up.

“This is something that's common with Biblical legends,” says Robert Cargill, assistant professor of classics and religious studies at the University of Iowa and editor of Biblical Archaeology Review. “Anytime it doesn't specifically say what happened to someone's body, it lends itself to all kinds of traditions about where it could have been.”

The story of John the Baptist comes to us from the New Testament, particularly the gospels (Matthew, Mark, Luke and John), and from Flavius Josephus’ work The Antiquities of the Jews. After living an ascetic life in the desert, John emerged into the lower Jordan Valley preaching about the imminent arrival of God’s judgment, and urging his followers to repent their sins and be baptized in preparation for the coming Messiah.

John the Baptist’s preparatory message attracted hundreds, perhaps thousands, of followers from Jerusalem and Judea. He made it clear that he himself was not the Messiah, and foretold the coming of Jesus: “one who is more powerful than I, whose sandals I am not worthy to carry.” (Matthew 3:11).

Many religious scholars agree that John’s subsequent baptism of Jesus in the River Jordan, described in three of the gospels (Matthew, Mark and Luke) and by a number of other canonical and non-canonical sources, is almost certainly a historical event. The archaeological site at Al-Maghtas, Jordan (identified as the Biblical “Bethany beyond the Jordan”) has been viewed as the baptism site since the late Roman-early Byzantine era. Most Christian denominations view Jesus' baptism as a major milestone and the basis for the Christian rite of baptism that has survived through the centuries.

According to Josephus, sometime after baptizing Jesus, John the Baptist was killed at the palace fortress of Machaerus, located near the Dead Sea in modern Jordan. Built by King Herod the Great, the palace was occupied at the time by his son and successor, known as Herod Antipas.

The Gospels of Matthew (Matthew 14:1–12) and Mark (Mark 6:14–29) recorded that Herod Antipas had John the Baptist arrested and imprisoned after the preacher condemned the king’s marriage to his wife, Herodias, as illegal, because she had previously been married to his own brother, Philip. Herod Antipas initially resisted killing John, because of his status as a holy man. But after his stepdaughter danced for him at his birthday party, he offered to give her anything she desired. Prompted by her mother, who resented John’s judgment of her marriage, Herodias’ daughter requested the head of John the Baptist on a platter.

In The Antiquities of the Jews (Book 18:116-19), Josephus confirmed that Herod Antipas “slew” John the Baptist after imprisoning him at Machaerus, because he feared John’s influence might enable him to start a rebellion. Josephus also identified Herodias’ daughter as Salome (the gospels don’t mention her name) but didn’t state that John was beheaded on her request.

Josephus didn’t mention where John the Baptist was buried, nor did the Bible, though the Gospel of Matthew stated that his disciples “came and took away the body and buried it, and went and told Jesus” (Matthew 14:12). From the fourth century (three centuries after these events took place), John’s burial place was traditionally believed to be at Sebastia (originally Samaria), now in Palestine.

What became of John the Baptist’s head, on the other hand, is a question that has tantalized relic seekers for centuries. “You get a thousand different traditions about where he was buried, where his head was buried, and stuff like that,” Cargill says.

According to different traditions, no fewer than four locations lay claim to the murdered saint’s head. In Damascus, Syria, the Umayyad Mosque was built in the eighth century A.D. on the site of a Christian church named for John the Baptist; his head is said to be buried in a shrine there. A skull identified as the head of John the Baptist is on display at the Church of San Silvestro in Capite in Rome, built to house artifacts from the Roman catacombs. The 13th-century cathedral in Amiens, France was built specifically to house the head of John the Baptist, which a Crusader supposedly brought back from Constantinople in 1206. And in Munich, Germany, the Residenz Museum includes John’s skull among a number of relics collected by Duke Wilhelm V of Bavaria with the Pope’s permission in the mid-16th century.

In addition, museums and monasteries in Istanbul, Egypt and Montenegro, among other locations, claim to have other body parts belonging to John the Baptist, including his right arm and right hand (with which he baptized Jesus).

In 2010, Bulgarian archaeologists announced that they had found a reliquary containing a number of bones in the ruins of a medieval monastery on Sveti Ivan (or “St. John,” in Bulgarian), a Black Sea island off Bulgaria's southern coast. Because a later monastery on the island was dedicated to John the Baptist, the researchers suggested these were likely the saint’s remains, pointing to a tiny sandstone box found alongside the reliquary, inscribed in Greek: "God, save your servant Thomas. To St John. June 24."

Radiocarbon dating and genetic testing later revealed the bones found on Sveti Ivan belonged to a man who lived in what is now the Middle East in the first century A.D., making it conceivable they could be John the Baptist’s—although there’s no way to prove them as such.

In the end, the competing claims to John the Baptist’s head (and other body parts) may say less about history than they do about the enduring power of relics relating to Jesus’ life and ministry. Like the Shroud of Turin or the Holy Grail, the head of John the Baptist has acquired a mythical, larger-than-life stature over the centuries, due to the prophet’s importance in Christ’s story.

“There has always been this belief that if you can just touch an object associated with Jesus, at the very least, it could help confirm one's faith,” Cargill explains. “And at the best, it might perform a miracle.”