Saint Marcellina was a 4th-century Christian ascetic born in Trier to a prominent Roman family. As the eldest sibling of Ambrose and Satyrus, she assumed responsibility for her brothers' upbringing following their father's death. She chose a life of consecrated virginity, receiving the veil from Pope Liberius and committing herself to rigorous prayer and fasting. Her profound devotion and strict lifestyle served as a model for others, particularly influencing her brother Ambrose during his tenure as Bishop of Milan.
Life and devotion

After moving to Rome, Marcellina embraced an austere lifestyle defined by continuous prayer and abstinence. She transformed her family residence into a church dedicated to Mary. When her brother Ambrose became Bishop of Milan, she moved to assist him, helping to promote asceticism among local women. She was a significant source of information for the biographer Paulinus the Deacon regarding the life of her brother.
Veneration and legacy
She died in Milan and was interred within the crypt of the Ambrosian Basilica. Recognized as a saint in Catholic and Orthodox traditions, her feast day is observed on 17 July. Her memory is preserved by the Sisters of St. Marcellina, who founded an educational institute in London named in her honor in 1955.
