The thieves broke into the crypt in St. Michigan's Church in Dublin and vandalized the burial ground before relaxing with their heads, Irish Church said.
The mummy is believed to be a soldier who fought in the crusades, a series of eight expeditions sanctioned by the church between the 11th and 13th centuries, resulting in a religious war between Christians and Muslims. Foreigners turned their bodies over while the head was removed and also desecrated the 400-year-old remains of a nun, according to the church.
Vandalism, which is being investigated by the police, was discovered Monday as a guide to prepare to open the church.
"I am shocked that someone would target this ancient tomb and detest the remnants of those who lie within it, said" Archbishop of Dublin, Diarmuid Martin, in a statement. "
" Not only have these individuals destroyed the holy crypt, but they have destroyed these historic mummies that have been preserved in St. Michan's for hundreds of years, "he added.
" I would appeal to those responsible for examining their conscience and returning the Crusaders leader to their rightful place. "
Most of the current St. Michan's building dates back to the 1
The crypt was previously vandalized in 1996.
"The actions of these people are devastating and sanctified. We are sorry for the damage caused, "said Archdeacon David Pierpoint, President of the Christ Church Cathedral Cathedral of Parishes, of which the Church is a member.
" I would appeal to someone with information to contact Garda (Irish Police) ", he added.