Sometime after 1229, Cletus invited Franciscans to Eger, where he established their monastery. Formerly, some historians – including Márton Szentiványi – erroneously considered this was the first Franciscan convent in Hungary. Cletus also established his clan's monastery on 16 May 1232, dedicated to the Blessed Virgin. The monastery was called Bélháromkút Abbey ("Trium fontium de Beel"), because it was erected between three spring waters near present-day Bélapátfalva, the ancient estate of the Bél kindred (his secular relatives became patrons of the monastery). Upon the intercession of papal legate Giacomo di Pecorari, Cletus invited Cistercians from Pilis Abbey to his newly established monastery. Cletus donated the villages of Apátfalva, Királd, Ostoros, Arnót, Horváti, Mercse, Csokva, Dochond, Pazman, Medsa, Magy, Kisdukány, Csen and Velyn, in addition to three fishponds along the river Tisza to the Bélháromkút Abbey. With the consent of the Eger Chapter, Cletus also granted the fiftieth part of the episcopal tithe to the monastery. His donations were confirmed by Pope Gregory IX in 1239 and Pope Innocent IV in 1253. The establishing charter of the Bélháromkút Abbey was transcribed by Bishop Csanád Telegdi in 1330. Beside the two aforementioned convents, Cletus re-established the St. James hospital in Eger, when he subordinated the institution again to help the poor and sick, overriding the decision of his unnamed predecessors (possibly Katapán and Thomas), who converted the hospital into a church benefice. Pope Gregory IX confirmed this act on 7 March 1240 upon the request of its rector.
