Did Mary remain a virgin her whole life?

Yes. The Catholic Church teaches as an article of faith that Mary was ever-virgin: a virgin before, during, and after the birth of Christ. This teaching, rooted in Scripture and Tradition, was affirmed by the Fathers and defined at a Roman synod in 649, and is taught today in the Catechism (CCC 499-507).

The Catholic Church has always confessed that Mary remained a virgin her entire life, not merely before the birth of Jesus but throughout it, and afterward as well. This is why the Church calls her Aeiparthenos, the Ever-Virgin, a title honored in both East and West from the earliest centuries.

Virginity before, during, and after the birth of Christ

Mary's virginal conception of Jesus is affirmed directly in Scripture: when the angel Gabriel announces she will bear a son, she asks, How shall this be done, because I know not man? (Luke 1:34), showing her firm intention of virginity even within marriage to Joseph. The Church further teaches that Mary's virginity was not interrupted by Christ's birth itself, which occurred without violation of her physical integrity, a mystery the Fathers described as a virginal and miraculous birth. Finally, the Church holds that Mary remained a virgin after the birth of Christ as well, having no other children.

What about the brothers of Jesus?

Some point to Gospel references to the brethren of the Lord, such as James, Joses, Simon, and Judas (Matthew 13:55), as evidence against Mary's perpetual virginity. Catholic tradition, following ancient Jewish and Semitic usage where brethren could denote close kinsmen or cousins, understands these as relatives of Jesus rather than other children of Mary; Genesis 13:8 shows the same broad kinship usage of brother in Scripture, where Abraham calls his nephew Lot his brother. St. Jerome argued this case at length against the view of Helvidius, defending Mary's perpetual virginity as apostolic teaching.

Furthermore, from the Cross, Jesus entrusts his mother to the care of the disciple John rather than to any sibling (John 19:26-27), a gesture that would be unusual if Mary had other sons who could have cared for her according to Jewish custom.

The Church's definitive teaching

The perpetual virginity of Mary was affirmed by a Roman synod held in 649 under Pope St. Martin I, which explicitly professed her virginity before, during, and after giving birth. This teaching was echoed by the Fathers of the Church, including Ambrose, Jerome, and Augustine, and it stands today as settled Catholic doctrine, summarized in the Catechism, which honors Mary as Ever-Virgin (CCC 499-507). Her perpetual virginity is understood not as a mere biological fact but as a sign of her total consecration to God and her unique role as Mother of God and Mother of the Church.