Theotonius (c. 1082 - 1162) was a Canon Regular and royal advisor. He is noted in Portugal, for being the first prior of the Monastery of the Holy Cross in Coimbra, Portugal. He is celebrated as the reformer of religious life in Portugal, and is the first Portuguese saint.
The Monastery of the Holy Cross (Portuguese: Mosteiro da Santa Cruz), also known as the Church of the Holy Cross, is a National Monument in Coimbra, Portugal. Because the first two kings of Portugal are buried in the church it was granted the status of National Pantheon.
Founded in 1131 outside the protecting walls of Coimbra, the Monastery of the Holy Cross was the most important monastic house during the early days of the Portuguese monarchy. Saint Theotonius founded this community of Canons Regular of the Holy Cross of Coimbra and served as their first prior. The monastery and church were erected between 1132 and 1223.