Borgo di Ostia Antica (Gregoriopoli)

Gregoriopoli is a fortified medieval settlement at Ostia, developed around a papal citadel near the Tiber's former course.

Why it matters

The borgo preserves a rare example of a continuously inhabited fortified settlement in the Roman area. Its walls, tower and terraced houses reflect successive efforts to maintain a community near the river mouth after the ancient port city declined.

What to notice

The settlement's compact plan gathers terraced houses and defensive walls around Piazza della Rocca. Heraldic stones associated with Cardinal Guglielmo d'Estouteville mark phases of restoration, while the neighbouring castle and church form important parts of the historic ensemble.

Context and history

Pope Gregory IV established a fortified settlement here in the ninth century as protection against raids. Martin V added a stronghold around 1400, and Cardinal d'Estouteville restored the walls and developed rows of terraced houses in the fifteenth century. The 1557 flood shifted the Tiber's course and altered the settlement's relationship with the river.