Medean (Civ3)/Civilopedia

The kingdom of Medes appeared relatively late in Mesopotamian history. Its founder, Deioces of Zagros, united a number of independent principalities in what is now western Iran to oppose the growing influence of Assyria to the south and the depredations of the Scythians to the north. Deioces' efforts were successful but eventually Medes fell victim to Scythian invasions and came to be dominated by the fierce northern horsemen.
This all changed when Cyaxares of Media came to power in the 7th century BC. In a stunning act of intrigue and treachery, Cyaxares engineered the assassination of virtually all of the Scythian leaders and kings, sending Medes' new masters into chaos and disarray. Once his power had been thus consolidated, Cyaxares was able to reorganize the army into groups of specialists (rather than the dominant tradition of having each warrior practice with all weapons). He then signed an alliance treaty with Babylon aimed at getting rid of Assyria once and for all. This the two kingdoms achieved within Cyaxares' lifetime, as Assyria could not fend both of them off at once. When Assyria had been overrun, the Medeans controlled all of western Iran, the southern Caucasus, and a big chunk of what is now eastern Turkey. After Cyaxares' death, though, Babylon grew wary of its ally, and sought to undermine it. The rise of a new great power in Mesopotamia, Persia, combined with the withdrawal of Babylon's friendship, proved too much for Medes to overcome, and by 550 BC the once-mighty Medean kingdom had become a mere province of Persia.