The "Dark Ages" is a historical periodization

Periodization

Periodization is the attempt to categorize or divide time into named blocks. The result is a descriptive abstraction that provides a useful handle on periods of time with relatively stable characteristics...

 emphasizing the cultural and economic deterioration that supposedly occurred in Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

 following the decline of the Roman Empire

Decline of the Roman Empire

The decline of the Roman Empire refers to the gradual societal collapse of the Western Roman Empire. Many theories of causality prevail, but most concern the disintegration of political, economic, military, and other social institutions, in tandem with foreign invasions and usurpers from within the...

. The label employs traditional light-versus-darkness imagery to contrast the "darkness" of the period with earlier and later periods of "light". The period was characterized by a scarcity of historical and other written records for much of the period, rendering it obscure to historians.