You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Heresy

Context:
Constantine the Great, who along with Licinius had decreed toleration of Christianity in the Roman Empire by what is commonly called the "Edict of Milan", and was the first Roman Emperor baptized, set precedents for later policy. By Roman law the Emperor was Pontifex Maximus, the high priest of the College of Pontiffs (Collegium Pontificum) of all recognized religions in ancient Rome. To put an end to the doctrinal debate initiated by Arius, Constantine called the first of what would afterwards be called the ecumenical councils and then enforced orthodoxy by Imperial authority.

Question:
What was the high priest in the College of Pontiffs called?

Pontifex Maximus