'Decline and Fall of the Western Roman Empire - Part II'
The West, modern Europe and America, are the modern successors to the Greeks and Romans. Our architecture, law, philosophy, politics etc.
The Western Roman Empire's enemies used to be outside their borders, but eventually they let in hundreds of thousands of barbarian refugee, fleeing form the wars and persecution of Attila the Hun and even gave them land to settle on.
This was all done for short-term considerations such as needing extra troops against potential usurpers without any long-term consideration.
Then a hundred years later these people where carving up Kingdoms within the borders of the Roman Empire. Eventually they crossed over to North Africa, took over the bulk of their food supplying lands and carved up a new barbarian Kingdom right across the sea.
At this stage barbarian Generals controlled the bulk of the Roman army. Roman citizens had to pay massive taxes and were heavily demoralised under increased government oppression to fund the Army which was even struggling to round up conscripts while at the same time the economy was straining with heavy inflation and the money devaluating every year due to mixing cheaper metals into the gold and silver. Until the 'gold' coins were basically not gold anymore.
The 'Roman Empire' was then just scattered enclaves across Europe and Italy.
Then eventually the Commander in Chief, a Barbarian, walks in the palace and sends the Roman Emperor into early retirement and declared himself King of what was left of the Roman Empire; Italy.
And that was the end of the Western Roman Empire and complete Germanic barbarian rule over Western Europe.
This lead to the Dark Ages and Europe started to recover about 1000 years later during the Renaissance and then the Enlightenment. Both of which looked towards the Romans and Greeks for inspiration.