VATICAN CITY  — Tattooed mummies, Crusaders who branded their foreheads with crosses and inked Maori warriors were fodder for an unusual conference at a Vatican university Tuesday on how tattoos shape identity.

“Into the Skin: identity, symbols and history of permanent body marks” was the brainchild of a Christian arts association and Israel’s envoy to the Holy See, an unlikely participant given Judaism’s prohibition of tattooing.

Ambassador Mordechay Lewy acknowledged the paradox, saying the living memory of Auschwitz’s tattooed serial numbers added a layer to Jewish aversion to tattoos, which many Orthodox rabbis forbid because it alters the human body as a divine creation.

Yet Lewy is a respected expert in the field – and a critic of what he calls today’s “commercialization” of an important aspect of cultural history.

Tattoos “can symbolize a social rank, identify ethnic affiliation, indicate experience of religious pilgrimage or of a rite of passage,” he told the  two-day conference, which was held at the Vatican’s Pontifical Urbaniana University.

The presentations gave an eye-opening look at the  use of tattooing over time. Luc Renaut of the University of Poitiers spoke of the tattoos on mummies unearthed in Egypt, saying they’d probably been married to Nubian chiefs  and were “living trophies” that increased the chief’s prestige.

Mystics over time have claimed the “stigmata” – the wounds that imitate Christ’s wounds from his crucifixion.

And even today, many players on New Zealand’s All Blacks rugby team sport the traditional tattoos of the country’s Maori indigenous peoples, said Sean Mallon of the Museum of New Zealand.