According to the pontificals, he was the son of one Rufinus, and a
native of Aquileia. He had served the Church among the clergy at Rome
many years under Adrian and Antoninus Pius,[115] when, according to
Tillemont, in the fourth year of the reign of the latter he succeeded
St. Hyginus in the papacy in 142. He condemned the heresiarch
Valentinus, and rejected Marcion, who came from Pontus to Rome after
the death of Hyginus, as we have related elsewhere. The conflicts
which St. Pius sustained obtained him the title of martyr, which is
given him not only in Usuard’s Martyrology, but also in many others
more ancient; though Fontanini, a most judicious and learned critic,
strenuously maintains, against Tillemont, that he died by the sword.
He passed to a better life in 157, and was buried at the foot of the
Vatican hill on the 11th of July. See Tillemont, t. 2, p. 312, and
especially Fontanini, who discusses at length all things relating to
this pope, in his Historia Literaria Aquileiensis, l. 2, c. 3 and 4.