What was the original meaning of the Dark Ages and what meaning did it gain over time?

The Dark Ages is a historical periodization used originally for the Middle Ages, which emphasizes the cultural and economic deterioration that supposedly occurred in Western Europe following the decline of the Roman Empire. The label employs traditional light-versus-darkness imagery to contrast the "darkness" of the period with earlier and later periods of "light".The term "Dark Age" derives from the Latin saeculum obscurum, originally applied by Caesar Baronius in 1602 to a tumultuous period in the 10th and 11th centuries.Popular culture has further expanded on it as a vehicle to depict the early Middle Ages as a time of backwardness, extending its pejorative use and expanding its scope. It now means any period of supposed unenlightenment.