I note that the Titans of Ether have a timeline. Here’s how U3.5 fits into it:
[71 P.B.]
The Stranger reappears in Sosaria and journeys with a party of adventurers on a quest to vanquish Exodus.
The lost island of Ambrosia is rediscovered.
The Stranger consults with the Time Lord for the first time and gleans the means by which he might destroy Exodus.
The Stranger and his companions destroy Exodus in his Castle. This triggers a violent series of cataclysms that rearrange much of the land, destroying several cities in the process. The destruction is likely the result of Exodus losing control over his transformation mechanisms, which he used to raise the Isle of Fire to the surface with earlier on. Due to his interface with the natural world being destroyed, most of the towns of the Lands of Lord British are utterly destroyed in this cataclysm, except for Fawn, Montor East, Moon, Yew, Paws and the capital town of Britain. The Tower of Knowledge and the Pillars of Protection are both destroyed. The cult of Truth disappears from history altogether from this point on.
General Jakher, commander of Lord British’s army, defeats the forces of Exodus in a massive battle on the Bloody Plains. Thousands of soldiers die on both sides, including General Jakher. Large catacombs are built beneath the Bloody plains to contain the fallen soldiers of both sides.
Nearly seventy years pass as the world recovers from the devastation and anarchy that Exodus had brought. Famine, plagues, rioting, and wars divide the city-states for decades. Lord British keeps the city-states together as best as he can.
It is noted that Lord British and many of his offworld associates do not seem to age.
Moon has become a despicable city full of unscrupulous wizards and dishonest mages. Erstam’s experiments have met with some success. He has barely aged since searching for the secrets of immortality. Erstam conducts shady deals with contacts in Montor East and Fawn. Both of these cities are crumbling economically and physically.
[0000 A.B.]
The current calendar begins.
City-states band together and form Britannia, electing Lord British as Sovereign ruler and Monarch. The Kingdom of Britannia is thus formed.
The system of virtues is established. Yew is given the representation of Justice, and Britain the representation of Compassion. Moon is cleansed of the corrupt mages inhabiting it, much to the dismay of Erstam, and the city is renamed to Moonglow, representing Honesty. Construction on five towns, representing a virtue each, commences.
The Council of Wizards is established, made up of surviving mages from the old Cult of Runes. The mages do away with the old system of magicka levels based on jewel types and embrace the eight circles of magic, expanding the usage of magery to its fullest extent.
Construction on the eight shrines of virtue begins by order of the Council of Wizards.
Azure, first of the great tinkers of Minoc, crafts the eight runes of virtue.
The Council of Wizards creates the eight coloured stones of virtue. Each stone is placed within one of the great dungeons. The wizards hope to stem the evil within the dungeons through the use of these magical stones.
Lord British commissions three Shrines of Principle to be built on the Isle of Fire, the former abode of Exodus.
“The Quest of the Avatar” is announced by Lord British. The quest is meant to offer a new way of life to the citizens of Britannia to find happiness through spiritual fulfillment.
Magincia loses sight of its embodiment of the virtue of humility and the city turns to decadence, materialism, and pride.
[0005 A.B.]
Fawn and Montor East are in near ruin and are abandoned. Erstam and the people of Montor East, Fawn, and many residents of Moon that lived there before its cleansing, protest Lord British’s system of virtues and leave Britannia for Serpent Isle after discovering the Serpent Pillars.
The three great keeps of the principles are erected: Empath Abbey, the Lycaeum, and Serpent’s Hold. Serpent’s Hold is built upon the ruins of Montor East.
Meanwhile, on the other side of the world, the gargoyles summon the spirits of Mondain, Minax, and Exodus to inhabit their three Shrines of Principle. Exodus’ summoning causes the Isle of Fire to sink under the sea, not to be seen again for over three centuries.
Sir Percy rids the islands near the Cape of Heroes of evil dragons and becomes the first member of the Order of the Silver Serpent. The Order of the Silver Serpent is officially established by Lord British, with Serpent’s Hold serving as the order’s headquarters.
Sentri is given the title of Baron and oversees Serpent’s Hold.
[0045 A.B.]
The town of Magincia is destroyed by daemons under the leadership of a powerful daemon known as ‘Virtuebane’, presumably due to the pride of its inhabitants.