Al-Masjid an-Nabawi, the Prophet's Mosque, originated after Muhammad's migration from Mecca to Medina in 622 CE, the event known as the Hijra. The first enclosure stood beside his residence and was built with sun-dried brick, palm trunks, and a roof of palm leaves around an open courtyard. Muhammad participated in the work. The mosque served prayer, teaching, consultation, judgment, reception of delegations, and care for poor companions, making it a community center as well as a sacred building in the emerging Muslim polity.

The original prayer direction faced Jerusalem before the qibla changed toward the Kaaba in Mecca. Muhammad introduced a pulpit and led communal worship, while the shaded Suffa sheltered students and people without homes. His wives' rooms adjoined the enclosure. After his death in 632, he was buried in Aisha's chamber; the first caliphs Abu Bakr and Umar were later buried beside him. Expansion under Umar and reconstruction under Uthman replaced palm columns with stone and enlarged the precinct as Medina's population and the Muslim community grew.

Umayyad Caliph al-Walid I ordered a major rebuilding in the early eighth century through his governor Umar ibn Abd al-Aziz. It incorporated the former domestic rooms into the mosque, enclosed the tomb area, and introduced mosaics, masonry arcades, and minarets using craftsmen from different parts of the empire. Abbasid caliphs expanded the building northward and sponsored repairs. Although political capitals moved to Damascus, Baghdad, Cairo, and elsewhere, Medina remained a center of scholarship and pilgrimage, and the mosque retained unique authority as the site associated directly with Muhammad's life and burial.

Fire, structural failure, and repeated rebuilding reshaped the medieval mosque. Mamluk rulers repaired roofs and minarets, and Sultan Qaitbay erected a stone dome over the burial chamber in the late fifteenth century. Ottoman sultans restored walls, gates, calligraphy, and furnishings. Mahmud II rebuilt the dome in the nineteenth century, and it was later painted green, creating the landmark known as the Green Dome. These campaigns preserved sacred location and selected features, but the visible complex never remained an untouched seventh-century structure.

Saudi control began in 1925, followed by expansions on an unprecedented scale. Works under Kings Abdulaziz, Faisal, Fahd, and later rulers added reinforced-concrete prayer halls, tall minarets, courtyards, mechanical cooling, retractable shade umbrellas, escalators, and vast service infrastructure. Buildings and neighborhoods around the mosque were demolished to accommodate pilgrims and hotels, a transformation that improved capacity while erasing much of historic Medina's urban fabric. Management also regulates access to the Rawda and burial area amid theological concerns about practices that might be interpreted as excessive veneration.

The Prophet's Mosque is Islam's second holiest mosque after al-Masjid al-Haram in Mecca and receives millions of worshippers and visitors. It is an active sanctuary rather than an archaeological monument, so ritual, safety, crowd movement, cleanliness, and accessibility guide decisions alongside heritage. Its historical significance lies in continuity of place through radical architectural change. The simple first courtyard established patterns of communal worship and social life that influenced mosque design worldwide, while every enlargement records how successive Muslim societies expressed devotion, sovereignty, technical capacity, and responsibility for an exceptionally sacred site.