[Anitius Severinus Boethius]

Romans weren’t around 3500 years ago and Rome could never have surrendered to Islam.

Rome fell in 476AD and Islam was founded around 610AD.

[kenavi]

Rome fell in 476AD and Islam was founded around 610AD.

Of course, Constantinople, the capital of the successor of the Roman Empire, did fall to the Turks.

[muawiyah]

The Eastern Roman Empire fell in the early 1400s after having been totally supplanted by Islamicized Turks (see: Ottoman Empire)

One of the most negative consequences of the contact between Islam and the Eastern Roman Empire was the Moslem adoption of a form of government popular among the Romans ~ the "emperor" or "dictator". Sharia law, right up to 1000 AD or thereabouts when "the book was closed" drew heavily from the worst elements of Eastern law.

To a considerable degree the Ottoman Empire and the Roman Empire had the same faults for the same reasons.

The Western Empire technically "fell" in the 400s, but that was simply a change in dynasty since the replacements sought to preserve the Western Empire.

The Dark Ages happened with a bang in the mid 500s and had NOTHING to do with wandering bands of savages!