After the fall of the Western Roman Empire, Europe devolved into chaos.
To the east, the Bulgarian and Byzantine Empires where created. The Rus also arrived on the scene.
To the West, northern Italy fell under the control of the Holy Roman Empire, save Venice, as did Germany. Spain and England where divided, however eventually England became a unified nation after the Viking Invasion. The papacy would eventually become a puppet of the French in the later middle ages.
But what if the Holy Roman Empire had been larger? Say Britain remains divided, Anglo-Saxon kingdoms against Celtic kingdoms. If France had become more divided? If the Papacy and the Holy Roman Empire had been on better terms? Perhaps the French States would become electorates of the Holy Roman Empire.
So the borders of the Holy Roman Empire would now be to Hungary and Poland, the British Kingdoms, the Danes and Iberia. Iberia would eventually go through the reconquest and become several nations. Britain might never unite in William the conqueror never showed up. (Perhaps Normandy and Brittany where trying to exert their independence from the HRE...)
Eventually the Holy Roman Empire would break apart into many nations.
What do you think, and can you find a good POD to create this timeline?