Astyages succeeded his father in 585 BCE, following the Battle of Halys, which ended a five-year war between the Lydians and the Medes. He inherited a large empire, ruled in alliance with his two brothers-in-law, Croesus of Lydia and Nebuchadnezzar of Babylon, whose wife, Amytis, Astyages' sister, was the queen for whom Nebuchadnezzar was said to have built the Hanging Gardens of Babylon. but due to the recent evidence, the garden was likely built by the Assyrian King Sennacherib. Married to Aryenis, the sister of King Croesus of Lydia, to seal the treaty between the two empires, Astyages ascended to the Median throne upon his father's death later that year.