Obviously, there have been other periods of "Dark Ages" in history - like ancient Greece following the bronze age collapse. So what was the rest of the world doing during the European dark age? Where there other societies experiencing "renaissances"?
If you use something like 500-700 as your range for the "Dark Ages," which is about the range that's popular now, the tail end of the timeframe overlaps with the Umayyads at the height of their power and influence and the early parts of China's Tang Dynasty Golden Age.