Marcellus

Chambers's Encyclopaedia, Volume 7: Maltebrun to Pearson, p. 37

Marcellus, the name of two popes, of whom the second deserves special notice, as having, when Cardinal Marcello Cervini, taken a very prominent part in the discussions of the Council of Trent, over which he was appointed to preside as legate of Julius III. He was elected pope 10th April 1555, and survived his elevation but twenty-two days. He did not follow the usual custom of laying aside his baptismal name and assuming a new one.

Source scan(s): p. 0046