Someone beheaded 'The Crusader': Vandals decapitate 800-year-old mummy in Dublin church The 400-year-old remains of a nun were also damaged in the incident.

LONDON -- Someone beheaded "The Crusader."

Irish police have launched an investigation after a crypt at a Dublin church was vandalized by thieves who removed and stole the head of an historic, 800-year-old mummy known locally as “The Crusader.”

The damage was discovered on Monday by a tour guide who was opening St Michan’s Church for visitors. The Irish Police, known as the Gardaí, are currently examining the scene. They told ABC News in a statement that the break-in is believed to have occurred either late on Saturday night or early Sunday morning.

The crypt was “badly damaged” and a number of other mummies were “desecrated” by the vandals, including the 400-year-old remains of a nun, according to the Church of Ireland. The 800-year-old mummy, “The Crusader,” was found turned upside down with its head removed.

The Archbishop of Dublin, Michael Jackson, expressed his “shock” at the incident and called for those who removed the head to return it to the church.

I would appeal to those responsible to examine their consciences and return the head of The Crusader to its rightful place.

“I am shocked that someone would target this ancient burial place and desecrate the remains of those lying within it,” he said in a statement. “Not only have these individuals desecrated the sacred crypt but they have destroyed these historic mummies which have been preserved in St Michan’s for hundreds of years. I would appeal to those responsible to examine their consciences and return the head of The Crusader to its rightful place.”

This is not the first time the crypt of St Michan’s has been violated.

St Michan’s Church contains five burial vaults housing mummified remains, according to the Church’s website. The dry atmosphere in the vaults helps to preserve the mummies and their coffins.

In 1996 a similar incident occurred, and Archdeacon David Pierpoint, St Michan’s parish priest, said it was “very frustrating” that the crypt had been targeted once again.

“The actions of these people are devastating and sacrilegious,” he said. “We are upset at the amount of damage that has been caused. But also, the crypt will have to close so tourists will not be able to visit.”