"on account of the Eleven Thousand Virgins"
The Church of St. Ursula, in Cologne, Germany, is said to be built on the site where the virgins were killed.

According to legend, Ursula, a Romano-British princess, set sail to join her future  husband, a pagan of Brittany, along with 11,000 virginal handmaidens.  A storm brought them over the sea in a single day. Ursula declared that before her marriage she would undertake a pan-European pilgrimage. In Rome she persuaded the Pope, Cyriacus (unknown in the pontifical records), and Sulpicius, Bishop of Ravenna, to join here and her followers. Cologne was being besieged by Huns, and it was there that all the virgins were beheaded. Ursula was shot dead.

Church of St. Ursula
Creative Commons Attribution Share AlikeChurch of St. Ursula - Credit: Warburg