(Nabu-shum-ma-u-kin or Nabu-MU-u-kin) Fifth King of the eighth dynasty of Babylon (dynasty "E"), successor, and perhaps son of Shamash-Mudammiq. NABU-Shuma-Ukin I, had managed to settle in the northern region of Arrapha and stabilize the country, might agree - despite some campaigns in which he/she was defeated - with the Assyrian king Adad-Nirari II; both rulers signed a treaty in which, in addition to fixing the borders between their territories, agreed to marriage each monarch with the daughter of another, known by the synchronous Chronicle. That Treaty allowed him to keep the peace with the successor of Adad-Nirari II, Tukulti-Ninurta II. According to a Babylonian Chronicle, during some years Nabu-Shuma-Ukin I could not celebrate the festivities of Akitu 'New year'. On the throne of Babylon, his son succeeded him Nabu-Apla-Iddina.