When Dom Crescónio became bishop of Coimbra in 1092, he brought the ten-year-old Theotonius with him and entrusted his further education to the care of a young seminarian, Tello.

[2] After the death of Bishop Crescónio in 1098, Theotonius went to Viseu, where his uncle named Teodorico was prior of the Cathedral Chapter of Santa Maria.

During his time of preparation for the priesthood, Theotonius progressed through the minor ecclesiastic orders with great diligence and piety.

The young priest was appointed a canon of the Cathedral Chapter of Viseu, which was a college of clerics who served as advisors to the bishop.

[6] Theotonius was asked many times by Count Henry and Queen Teresa, to assume the office of bishop.

Theotonius' experience in Holy Land resulted in both an increased devotion to the Passion and an intention to found a religious order following the Augustinian Rule.

Work began on the Monastery of the Holy Cross and of the Blessed Mary Mother of God, on 28 June 1131.

Although his counsel was sought by Afonso Henriques, Theotonius did not hesitate to reprove the king or queen if he thought them in the wrong.

[7] One day, in the church of Viseu, he preached a sermon against co-habitation in the presence of the widowed queen and her lover, Count Fernando.

[6] He was offered the bishopric of Viseu and later Coimbra, but declined, partly because he suspected the queen was attempting to bribe him.

The Royal Confraternity of Saint Theotonius, founded on 2 November 2000, under the royal protection of Dom Miguel de Bragança, Duke of Viseu, Infante of Portugal, is a secular organization of the faithful with common ends, a group of men willingly desiring to defend the origins and Christian values, maintain and honor the spirit of and remember and promote devotion to Saint Theotonius.