Saint Kilian, also spelled Killian or Cillian was born in Mullagh, Co. Cavan in 640 A.D. in Cloughballybeg, a short distance south-east of where his Holy Well is now situated.
He eventually founded his own monastic foundation of Kilmakilloge harbour in the Kenmare area, from where he and his companions left Ireland and were directed by Pope Conan to Germany.
He became an Irish missionary, bishop and the apostle of Franconia (nowadays the northern part of Bavaria), where he began his labours towards the end of the 7th century.
There are several biographies of him. The oldest texts which refer to him are an 8th century necrology at Würzburg and the notice by Hrabanus Maurus in his martyrology.
According to Maurus, Kilian was a native of Ireland, whence with eleven companions he went to eastern Franconia and Thuringia.
After having preached the Gospel in Würzburg, he succeeded in converting to Christianity the local lord, Duke Gozbert, and much of the population.
There came a time when Kilian told the Duke that he was in violation of sacred scripture by having an affair with his brother’s widow, Geilana. Geilana heard of Kilian’s words, and, furious at his interference in her domestic affairs, hired two assassins to murder Kilian and his two companions, Colman and Totnan, while Gosbert was away hunting. The year was around 689 A.D.
From the time that his relics were first enshrined in the cathedral of Würzburg, his cult spread throughout Central Europe, ultimately to Italy, Great Britain and further afield.
The elevation of the relics of the three martyrs was performed by Burchard, the first Bishop of Würzburg.