Monica of Hippo (feast day, 4 May)
The mother of Augustine of Hippo, one of the most important "fathers of the church," Monica is an early fourth-century Christian (her birth is variously dated as 322 or 331 or 333 CE) born in Tagaste, North Africa (now Souk Ahras, Algeria).
Basilica of St. Augustine, Rome
Monica was married to a Roman pagan named Patricius--most of what we know about Monica comes from what Augustine tells us in his Confessions, written between 397 and 400. Augustine describes his father as an unfaithful husband and a violent man, one who seems to have been annoyed by his wife's piety and devotions, but, at least according to Augustine, Patricius did not strike Monica or otherwise harm her physically, though he caused her a great deal of anguish and emotional pain.
While Patricius did not allow Monica to baptize their children, Monica nevertheless prayed for her Augustine's conversion to Christianity--and wept for his many transgressions. She followed him when he left Carthage for Rome and then Milan. Her son finally converted to Christianity in 386, and he was baptized in Milan in 387. Monica died in Ostia in 387, as mother and son were on their way back to Africa.
While Monica gained much admiration for her gentle persistence in urging her son to his conversion, there's one thing about Monica that I find hard to understand, much less to forgive. In his Confessions, Augustine writes movingly about his long relationship with an unnamed "concubine," the mother of his son Adeodatus ("gift from God"). Augustine lived with this woman for thirteen years and, as he writes, he loved her deeply. But, at his mother's insistence, he ultimately sent this unnamed woman away--not because she wasn't the beloved mother of his child, but because Monica wanted her son to make an advantageous marriage. Augustine kept their child with him.
(Saint Monica's feast day, 4 May, was first celebrated in the fifteenth century; the date was changed in the Roman Catholic calendar after 1969.)