The early Persian kings had tried to keep the religious ceremonies of Marduk. By the reign of Darius III, over-taxation and numerous wars had led to a deterioration of Babylon's main shrines and canals, and the disintegration of the region. Despite three rebellions in 522 BCE, 521 BCE and 482 BCE, the land and city of Babylon remained under Persian rule for two centuries. In 331 BCE, Alexander the Great took over. Under the Parthian Empire, Babylon continued to shrink and lose importance.