"At Cologne," says the Roman Martyrology, "the birth in heaven of St. Ursula and her holy companions, who were massacred by the Huns, out of hatred for the Christian religion and their virginal purity. Several are buried in this city."
(Psalm 118:46-47,1 from the Introit of Mass)
Da nobis, quaesumus, Dómine, Deus noster, sanctárum Vírginum et Mártyrum tuárum Ursulae et Sociárum ejus palmas incessábili devotióne venerári: ut, quas digna mente non póssumus celebráre, humílibus saltem frequentémus obséquiis.Grant us, we beseech Thee, O Lord our God, to reverence with unceasing devotion the victories of Thy holy virgins and martyrs Ursula and her companions; that those whom we cannot fitting celebrate, we may at least approach with lowly homage.
Article in the Catholic Encyclopaedia: http://www.newadvent.org/cathen/15225d.htm