Sinsharishkun (Sin-shar-ishkun; Sîn-šarru-iškun, c. 627 – 612 BC), who seems to have been the Saràkos (Saracus) of Berossus, was one of the last kings of the Assyrian empire, followed only by Ashur-uballit II.
He was the son of Ashurbanipal, and possibly the brother of the last Assyrian king, Ashur-uballit II (612–605 BC). He is the last king who has years attested in most Babylonian records. Little is known about this king due to the lack of sources for his time. It seems that he ascended the throne sometime around 627 BC. After the death of the powerful Ashurbanipal, the vast Assyrian Empire began to unravel, due to a series of bitter internal wars over who should rule. Sinsharishkun's rise to power was marred by severe violence, crippling internal civil war, and upheaval within the Assyrian Empire. He had to unseat the usurper Sin-shumu-lishir, who had deposed Ashur-etil-ilani, Sinsharishkun's older brother. During this confusion, a host of Assyria's many colonies and puppet states took advantage of the anarchy to quietly free themselves from Assyrian rule, and then Assyria faced threats from the Chaldeans, Babylonians, Medes, Persians, Scythians, and Cimmerians.
After temporarily defeating his rivals, Sinsharishkun faced a much larger threat. Babylon, a vassal state of Assyria for three centuries, took advantage of the anarchy within Assyria and rebelled under the previously unknown Nabopolassar, the leader of the Chaldean peoples of south eastern Mesopotamia, in 626 BC.