Complex sentence: The conquest of Media was a result of what is called the Persian revolt; the brouhaha was initially triggered by the actions of the Median ruler Astyages and quickly spread to other provinces as they allied with the Persians.
Split into simpler sentences: The conquest of Media was a result of what is called the "Persian Revolt". The brouhaha was initially triggered by the actions of the Median ruler Astyages, and was quickly spread to other provinces, as they allied with the Persians.