Pope Saint Julius I

The Architect of Christmas and Rome

Pope Saint Julius I began his pontificate as Bishop of Rome on February 6, 337, becoming the 34th successor of Saint Peter (35th Pope of the Catholic Church). He held this office for 15 years until his death on April 12, 352.

Little was known about his life before his pontificate. It is believed he was born in Rome, as his father, named "Rusticus," was a prominent Roman citizen born in the same city. Julius was ordained as a priest and appointed successor to Pope Mark, whose pontificate was brief in 336. After Mark's death, the papal seat remained vacant for four months—an unusually long period for which the reason is still unknown.

Saint Julius I was recognized as a loyal defender of the Catholic truth. Among the most relevant milestones of his rule were his firm stance against Arianism and the official establishment of the Solemnity of Christmas (Spanish version) every December 25th.

The beginnings of the Christian religion were complicated, marked by fierce persecutions of Christians by the Roman Empire.

Faith in Times of Imperial Transition

With the conversion of Emperor Constantine I (Western ruler from 306, until the unified empire in 337), the attacks stopped and freedom of worship was permitted. His conversion began in 312; in 313, he legalized Christianity with the Edict of Milan, and shortly before his death in 337, he was baptized.

Constantine ruled until May 337, so the first year of Julius I coincided with the transition toward the emperor’s sons as the new rulers. These were difficult times because many priests were in exile and several bishops had been removed from their dioceses. In this context, Arianism—a doctrine that denied the eternity of Jesus Christ by considering Him a created being—had spread widely. This position contradicted the Mystery of the Holy Trinity (Spanish version), which teaches the existence of one God in three distinct persons: Father, Son, and Holy Spirit.

Despite Arianism being declared a heresy at the Council of Nicaea (325), the conflict persisted. Pope Julius I decreed the return of the exiled bishops and bravely defended figures such as Saint Athanasius of Alexandria, facing Arian factions to preserve the unity of the faith.

The Legacy of the Archive and Christmas

During his papacy, Julius I not only fought for doctrine but also strengthened the authority of the Roman See. He ordered the collection and organization of all ecclesiastical acts using notarial criteria, thus creating the Archive of the Holy See. Thanks to this work, we can know the history of the Church over the last two thousand years.

For us at XmasVia, his most personal legacy is the change of the date of Christmas. In the year 352, Pope Julius I established that December 25th would be the date to celebrate the birth of the Baby Jesus, separating it from the feast of The Epiphany (January 6th) (Spanish version). This decision was ratified years later by his successor, Pope Liberius, in 354.

Promoter of Christian Architecture

Due to the rapid increase in the number of faithful, Pope Julius I was a great promoter of architecture in Rome in full transition. According to Roman laws of the time, properties had to be in a person's name; therefore, temples were identified with the name of the founder or benefactor (titulus) before being formally dedicated to a saint.

Pope Julius I applied two strategies: the consolidation of urban parishes (Tituli) and the creation of large pilgrimage centers (Basilicas) outside the city walls (extra muros). Among the different churches during the papacy of Saint Julius I, historical records (especially the Liber Pontificalis) highlight:

🟢 Basilica of Santa Maria in Trastevere: His most famous work. Initially called Titulus Iulii, it is considered one of the first churches in Rome officially dedicated to the Virgin Mary.

🟢 Basilica of the Twelve Apostles: Located near Trajan's Forum. Originally known as Titulus Iulia (or "Iuliana"), it was dedicated to the apostles Philip and James the Less in the 6th century.

🟢 Basilica on the Via Flaminia: A cemetery basilica built over the tomb of the martyr Saint Valentine. Today, its ruins are an archaeological site of great importance. Records also show his works on the Via Aurelia and the road to Porto.

Final Rest

Pope Saint Julius I passed away on April 12, 352. He was initially buried in the Catacombs of Calepodius, but due to his early veneration as a saint, his remains were later moved to the Basilica of Santa Maria in Trastevere, the church he himself helped to expand.

The Catholic Church celebrates the Memorial of Saint Julius I every April 12th.

✨ Coming Soon: A New Home for Christmas

We are excited to share that we are working on the full English version of our site! By the first Sunday of Advent 2026, the new en.xmasvia.com will be officially live, bringing you the magic and history of Christmas in your language.

Stay tuned for this new chapter of our journey!