a considerable sum in tribute to the Assyrian king. Diplomacy and incursions into Assyria The Cimmerians, a nomadic Indo-European people living in the southern Caucasus north of Assyria, had invaded Assyria during the reign of Ashurbanipal's father. After Esarhaddon defeated them, the Cimmerians turned to attack Lydia in western Anatolia, ruled by Gyges. After allegedly receiving advice from the Assyrian national deity Ashur in a dream, Gyges sent his diplomats to ask Ashurbanipal for assistance. The Assyrians did not even know that Lydia existed; after the two states successfully established communication with the help of interpreters, the Cimmerian invasion of Lydia was defeated 665. Two Cimmerian chiefs were imprisoned in Nineveh and large amounts of spoils were secured by Ashurbanipal's forces. The extent to which the Assyrian army was involved in the Lydian campaign is unknown, but it appears that Gyges was disappointed with the help since he just twelve years later broke his alliance with Ashurbanipal and allied with the increasingly independent Egypt instead. After this, Ashurbanipal cursed Gyges. When Lydia was overrun by its enemies 652–650 there was much rejoicing in Assyria. While the Assyrian forces were on campaign in Elam, an alliance of Persians, Cimmerians and Medes marched on Nineveh and managed to reach the city's walls. To counteract this threat, Ashurbanipal called on his Scythian allies and successfully defeated the enemy army. The Median king, Phraortes, is generally held to have been killed in the fighting. This attack is poorly documented and it is possible that Phraortes wasn't present at all and his unfortunate death instead belongs to a Median campaign during the reign of one of Ashurbanipal's successors. After his death 652, Gyges was succeeded by his son Ardys. Because the Scythians had driven the Cimmerians from their homes, the Cimmerians invaded Lydia again and successfully captured most of the kingdom. As his father had before him, Ardys also sent for aid from Ashurbanipal, stating that "You cursed my father and bad luck befell him; but bless me, your humble servant, and I will carry your yoke". It is unknown if any Assyrian aid arrived, but Lydia was successfully freed from the Cimmerians. They would not be driven out of Lydia completely until the reign of Ardys's grandson Alyattes. Civil war with Shamash-shum-ukin Rising tensions and rebellion Although Esarhaddon's inscriptions suggest that Shamash-shum-ukin should have been granted the entirety of Babylonia to rule, contemporary records