Rome Coliseum Historical Timeline

Almost every date in this building's record is damage, or the response to damage. It was inaugurated as an imperial gift on ground Nero had taken for himself, burned in a lightning fire, repaired repeatedly, half-collapsed in an earthquake, quarried for its stone, lived in, fortified as a castle, proposed as a wool factory and a bullring, and finally declared a martyrs' shrine — which is what stopped the quarrying.

The element to look for is the numbering over the arches. Eighty entrances ringed the ground floor, 76 of them for ordinary spectators, and the surviving stretch of outer wall still carries its Roman numerals: entrances XXIII to LIIII. The triangular brick wedges closing each end of that stretch are not Roman — they are nineteenth-century buttresses holding the broken wall up.

Chronology

1. 64 A.D. The Great Fire devastates the densely inhabited valley here, after which Nero seizes much of the area for his personal domain.
2. 70 A.D. The Siege of Jerusalem in the First Jewish–Roman War produces the spoils that fund the building.
3. 70–72 A.D. Construction begins under Vespasian, on the site of the lake in Nero's grounds. Some sources give 73–75.
4. 79 Vespasian dies with the building complete to the third storey.
5. 80 Titus finishes the top level; the inaugural games are held in 80 or 81. Dio Cassius records more than 9,000 wild animals killed during them, and accounts describe the arena flooded for a display of trained swimming horses and bulls.
6. 107 Trajan is said to have celebrated his Dacian victories with contests involving 11,000 animals and 10,000 gladiators across 123 days.
7. 217 A major fire, caused by lightning according to Dio Cassius, destroys the wooden upper levels of the interior. It is not fully repaired until about 240, with further repairs in 250 or 252 and again in 320.
8. 399 Honorius bans gladiatorial fights, and again in 404. They are last mentioned around 435. Animal hunts continue until at least 523.
9. 443 An inscription records restoration under Theodosius II and Valentinian III, possibly repairing damage from a major earthquake this year; more work follows in 484 and 508.
10. Late 6th century A small chapel is built into the structure. The vaulted spaces under the seating become housing and workshops, and are recorded as still being rented out as late as the 12th century.
11. c. 1200 The Frangipani family take the building over and fortify it, apparently using it as a castle.
12. 1349 The great earthquake. The outer south side, standing on less stable alluvial terrain, collapses — the single event that gave the Colosseum the shape it has today, and the source of the stone that went into Roman building for centuries.
13. 1377 After the papacy returns from Avignon, the Colosseum is restored by the Arciconfraternita del SS. Salvatore ad Sancta Sanctorum, who occupy a northern portion of it until as late as the early nineteenth century.
14. 1585–1590 Pope Sixtus V plans to convert it into a wool factory; the scheme dies with him. In 1671 Cardinal Paluzzo Altieri authorises bullfights here and a public outcry ends that too.
15. 1749 Benedict XIV endorses the view that this is a sacred site where early Christians were martyred, forbids the quarrying, and erects Stations of the Cross around the arena. They stand until February 1874.
16. 1807–1827 The façade is reinforced with the triangular brick wedges still visible at each end of the standing wall; the interior is repaired in 1831, 1846 and again in the 1930s.
17. 1810–1874 The arena substructure is partly excavated, and fully exposed under Mussolini in the 1930s.
18. 1993–2000 A major restoration addresses pollution damage, at a cost of 40 billion lire.
19. 2016 A €25 million privately sponsored restoration, agreed in 2011 and begun in 2013 after controversy over the public–private funding, is completed on 1 July.
20. 2025 The Commodus Passage opens to the public on 27 October, after restoration from October 2024 to September 2025.

What stopped the quarrying

A doctrinal decision, not an archaeological one. The Colosseum is not named in the medieval pilgrim itineraries, and the twelfth-century Mirabilia Urbis Romae puts the martyrdoms at the Circus Flaminius rather than here. The association was built up later — Pius V is said to have recommended that pilgrims gather sand from the arena as a relic, Fioravante Martinelli listed the building at the head of his 1653 catalogue of places sacred to the martyrs — until Benedict XIV acted on it in 1749 and banned the removal of stone. Whatever the history, the ban is why there is still a building here.