The “Dark Ages” was almost exclusively a European phenomenon. At the same time, Arabia was having a Golden Age.
They were also demolishing it at the same time. The ElMohads came into Spain from Morocco and demanded that everyone either accept Islam or expect the sword, so the great Jewish luminary Maimonides was forced to flee Moorish Spain with his family, beginning a lifetime of wandering and persecution. Alexander’s library was destroyed and as a result only 11 of Aristophanes’ plays are extant in their entirety. The Greek texts that the Mohammedans preserved were actually in the keeping of a Christian university in Damascus, where Algebra was also invented. They preserved it all by deciding not to burn the university down.
….. according to the Standard Islamic Narrative.
The so-called “Dark Ages” is a term invented by “Enlightenment” thinkers as to denigrate the Age of Faith that came before them, vaunting their own times as the “Age of Reason.”