NABU was a god, possibly of West Semitic origin, who became a major divine figure in Babylonia and Assyria of the first millennium BCE. He is first mentioned in official Babylonian documents of the time of Hammurabi (c. 1760 BCE) and may have been brought to Babylonia by the West Semites, who migrated there in large numbers in 2000–1800 BCE. Nabu was closely aligned with Marduk, whose minister, scribe, and ultimately son he was considered to be. The cult of Nabu began to spread in the Old Babylonian period. He grew in importance, becoming the god of the Ezida temple and the city of Borsippa by the beginning of the first millennium BCE. Nabu and Marduk are frequently mentioned together as the major pair of gods in Babylonia. Nabu appears in many personal names, including Nabu-Kudurri-usur (the biblical Nebuchadrezzar), which means "Nabu protect our boundaries." In Assyria, Nabu was revered as one of the most important gods, and his popularity was still increasing at the end of the Assyrian empire.
Nabu appeared in several important cultic festivals of the first millennium BCE. The most important was the Akitu, the spring New Year festival, which began when Nabu came in solemn procession from Borsippa to Babylon. The festival celebrated the reign of Marduk, but Nabu's participation was important enough that the absence of the festival during a period of political disturbance was referred to as "when Nabu did not come from Borsippa." He also appeared in the Babylonian celebration of his marriage to Nana and the Assyrian celebration of his marriage to Tashmetum.
Nabu is best known as the god of writing. He was the patron of scribes, displacing Nisaba, who played this role until the Old Babylonian period (1800–1590 BCE). As Marduk's scribe, Nabu was the writer of the tablets of destiny. He was associated with Marduk and Ea and consequently was considered a god of wisdom. By the end of Assyrian history Nabu was also assuming some of the characteristics of the hero figure Ninurta.
