Answer:
The event that best identifies the beginning of the so-called Dark Ages in Europe was the fall of the Roman Empire.
Step-by-step explanation:
The "Dark Ages" is a historical periodization that emphasizes the demographic, cultural and economic deteriorations that occurred in Europe following the decline of the Western Roman Empire. It is characterized by a relative scarcity of historical records and other writings, at least for some areas of Europe, thus making it obscure for historians.