Sometime in the second half of 2005, while he was supposed to be researching something else, Scarecrow developed the core idea, but it was not until the end of 2006 that the timeline was started.
The Point of Divergence for “The Song of Roland” is that in 778, when Charlemagne began his campaign into Spain, his Saracen ally Suleiman captures the city of Saragosa.
This POD leads to Charlemagne's Empire not falling apart after his death, and although an Emperor's power is reliant upon gaining and maintaining the support of the Kings in the Empire. Charlemagne's conquest of Denmark in 814 butterflied away some of the Vikings, leading to the rise of Northumbria in the British isles, and the establishment of two Norwegian established states: the Kingdom of Piktland and the Kingdom of Dublin by the end of the 9th Century.
The timeline is divided into sections known as Songs. Before each song is a brief prologue in which several of the key players in the period meet posthumously with a figure known as either Erasmus or Tim. His role in the timeline is not yet known. The actual timeline itself is written in two styles: The first, a narration by Erasmus, the second being written in third person point of view of significant events. That was until Scarecrow got bored, and decided to just write a Source based timeline like Decades of Darkness or Look to the West. Which would mean that he would have go back and change the old sections of the timeline, but he doesn't like to think about that to much.
The timeline is expected to run until the end of the 12th Century, covering roughly 4 centuries of alternate history.