She was the eldest sister to St. Ambrose and Satyrus, and after the
death of her father, who was prefect of the Gauls, removed to Rome
with her pious mother and brothers. She was discreet beyond her
years, and from her cradle sought with her whole heart the only thing
for which she was created and sent into the world. Being charged
at Rome with the education of her two brothers, she inspired them,
by words and example, with an ardent thirst of virtue. She taught
them that nobleness of blood cannot enhance merit, nor make men
more illustrious unless they despise it; and that learning is an
unpardonable crime and folly, if by it a man should desire to know
everything that is in heaven and earth but himself; for with the
true knowledge of ourselves are all our studies to begin and end, if
we desire to render them in any degree advantageous to ourselves.
She kindled in their tender breasts a vehement desire, not of the
show of virtue, but to become truly virtuous. In her whole conduct
all her view was only the glory of God. The better to pursue this
great end she resolved to renounce the world; and on Christmas-day,
in 352, she put on the religious habit, and received the veil from
the hands of pope Liberius, in St. Peter’s church, in presence of
an incredible multitude of people. The pope, in a short discourse
on that occasion, exhorted her frequently to love only our Lord
Jesus Christ, the chaste spouse of her soul, to live in continual
abstinence, mortification, silence, and prayer, and always to behave
herself in the church with the utmost respect and awe. He mentioned
to her the page of Alexander the Great, who, for fear of disturbing
the solemnity of a heathenish sacrifice by shaking off his hand a
piece of melted wax that was fallen upon it, let it burn him to the
bone.
Marcellina in her practice went beyond the most perfect lessons.
She fasted every day till evening; and sometimes passed whole days
without eating. She never touched any fare but what was of the
coarsest kinds, and drank only water. She never laid herself down
to rest till quite overcome with sleep. The greatest part both of
the day and night she devoted to prayer, pious reading, and tears of
divine love and compunction. St. Ambrose advised her in the decline
of her life to moderate her austerities, but always to redouble her
fervor in tears and holy prayer, especially in reciting often the
psalms, the Lord’s prayer, and likewise the creed, which he calls the
seal of a Christian, and the guard of our hearts. She continued at
Rome after the death of her mother, living not in a nunnery but in a
private house with one fervent virgin, the faithful companion of all
her holy exercises. St. Ambrose died in 397. She survived him, though
it is uncertain how long. Her name is mentioned in the Roman and
other Martyrologies on the 17th of July. See St. Ambrose, l. 3, de
Virgin. c. 1, 2, 3, 4, t. 2, p. 1741, and Ep. 20 et 22, ed. Ben. and
Cuper the Bollandist, t. 4, Julij, p. 231.