Started as King of Mercia earliest start (seven-fifty something AD, about five counties)
Slowly expand, become King of England
Vassals start gaining territory in Wales and Ireland
Form Kingdoms of Wales and Ireland, begin conquest of Scotland
Become Emperor of Britannia
Assist in Holy War for what is essentially southern Spain
Is best in Holy War, King of Southern Spain
Vassals somehow take over Lombardy and Sicily (Upper and Lower Italy)
Take over Rome
Adopt Cathar Catholic Heresy
Females can inherit
Defeat Catholics in Holy War
Gets to game pre-DLC start date (1100 or so)
Is Emperor of England, Scotland, Wales, Ireland, Spain and Italy, in open defiance of the Pope
Halfway through possible time
Game still going, dear god help.
Would have life and all thoughts consumed again. Just wish I could get achievements with custom characters.

Edit: Holy Fury/V3.0 is pretty fantastic