The Beginning
The planes are formed. Primal forces rage back and forth across the unformed mass of Being. Their struggles twist and deform the whole scope of existence as each seeks to be the guiding force for all that is. Good wrestles with Evil, and Law with Chaos. Out of this conflict was born the races of fiends and celestials. The fiends wage an eternal Blood War between the lawful Baatezu and the chaotic Tanar’ri, with the treacherous Yugoloths in between.

Eons Ago
The fiends and celestials discover Sigil, the City of Doors, which is inhabited solely by the mysterious dabus. Realising that Sigil’s portals allow instant travel to any plane in the multiverse, the fiends begin fighting for the city; not wanting Evil to reign unchecked across the planes, the celestials quickly join in. This battle ends swiftly with the appearance of the Lady of Pain. Her serene gaze kills the leaders of the warring celestials and fiends, forcing an uneasy peace.

Fifty Thousand Years Ago
Mortals start finding their way to Sigil. Coming from a thousand worlds on the Prime Material Plane, this influx of humans and other, stranger beings make Sigil the most cosmopolitan city in the multiverse.

Two Thousand Years Ago
The god Aoskar, the Keeper of Keys, has become the most highly worshipped deity in Sigil. Half of the planewalkers in Sigil whisper his name every time a portal is used. Although Aoskar is threatening to seize control of Sigil, the Lady of Pain does nothing – until one of her dabus starts worshipping the Keeper of Keys. Then she strikes – Aoskar’s Temple is destroyed, his worshippers exiled, and the god himself slain. Aoskar’s stone corpse floats in the Astral Plane.

One Thousand Five Hundred Years Ago
Realising that the power of belief can change the planes, mortals in Sigil begin to form political groups based upon philosophical ideologies. These are eventually formalised as the factions of Sigil.

One Thousand Years Ago
The Factol of the Expansionists, Vartus Timlin, begins making plans to depose the Lady of Pain as ruler of Sigil. His sword, Lightbringer, is rumoured to be an artifact of incredible power. However, Timlin vanishes into an extra-dimensional Maze created by the Lady of Pain. The Expansionists eventually die out.

Six Hundred and Thirty Years Ago
The Lady of Pain appears before the Factols of each of the 49 factions. She points at a dabus servant, and it creates a string of symbols that translate as:

By order of the Lady of Pain, there will be but 15 factions in Sigil. Organise thy colours by a fortnight hence – or die.

This decree ends the needless chaos of conflicting interest groups. The Lady of Pain killed nearly eighteen thousand; others left Sigil, amalgamated their ranks, or joined other factions. Ever since the so-called Great Upheaval, factions are born and die, but there are never more than fifteen at one time.

Four Hundred Years Ago
The Harmonium moves into the City of Doors from their homeworld, Ortho. After successfully applying for official status as a faction in the Hall of Speakers, the Harmonium decides to “reform” Sigil. They start acting as Sigil’s police force.

One Hundred Years Ago
The tanar’ri general Hapashemdus leads an invasion into Baator. It fails abysmally. The baatezu claim that their cornugon heroes destroyed the invasion; the tanar’ri found a convenient scapegoat to blame for sending weak troops to serve Hapashemdus.

Five Years Ago
A portal leading to the Maze imprisoning Vartus Timlin is discovered. The Fated, Harmonium, and Mercykillers factions all enter the Maze searching for the artifact Lightbringer; however, a team of Athar and Free League mercenaries rescue Vartus Timlin and capture Lightbringer. Timlin flees Sigil, and the sword ends up in the hands of the Dustmen.

One Year Ago
Duke Rowan Darkwood enters Sigil and becomes Factol of the Fated. His radical new taxation scheme makes the Fated wealthy; his charisma and willpower ensures that the fated are a strong force in the Hall of Speakers.

Nine Months Ago
Factol Mallin of the Mercykillers is killed when a riot starts in the Prison. He is replaced by a girl named Alisohn Nilesia. She institutes a new code of punishment in the Prison.

Recently
The factions have begun to agitate throughout Sigil. The Xaositects have been rioting; there have been attempts to arrest Factol Pentar of the Doomguard by the Harmonium for supposed instigation of chaos. A rash of murders has occurred throughout The Hive, The Clerk’s Ward and the Great Bazaar. Both the Free League and the Harmonium claim that somebody is targeting their members. The Harmonium have increased their presence in the city in an attempt to combat this most recent wave of crime. The elf instigating the crimes was put on trial and sentenced, but the crime in the city has yet to abate.