| Year | Event |
| Before Time | The Outlands and the central Spire form; access to the Outer Planes stabilizes. |
| Unknown | Sigil is created atop the Spire as a toroidal city floating above its peak. |
| Unknown | The Lady of Pain appears and asserts absolute control over Sigil. |
| Early Ages | Portals within Sigil multiply, linking all planes through keyed gateways. |
| Early Ages | Gods are barred from entering Sigil; divine proxies are tolerated but watched. |
| Ancient Era | Factions begin to form as philosophical responses to planar reality. |
| Ancient Era | The Dabus appear, maintaining Sigil and repairing its structure. |
| Middle Ages | Sigil becomes the primary planar trade hub and neutral ground. |
| Faction War (Planescape era) | Philosophical conflict erupts into open violence among the factions. |
| Faction War | The Lady of Pain intervenes; factions are banished or dismantled. |
| Post–Faction War | Sigil enters a period of enforced political minimalism. |
| Post–Faction War | Power structures shift toward guilds, cabals, and informal influence. |
| Modern Era | Sigil remains the City of Doors; neutral, dangerous, and indispensable. |
Sigil Timeline
A condensed record of the City of Doors, its enforced neutrality, and the consequences of attracting the Lady of Pain’s attention.