his father. Ashurbanipal became the king of Assyria in late 669 following Esarhaddon's death, having been crown prince for only three years. Upon his accession, he was possibly the most powerful person on the planet, but there appears to have been some fears of trouble. His grandmother Naqi'a wrote a treaty, dubbed the Zakutu Treaty by modern historians, in which she forced the royal family, aristocracy and all of Assyria to swear loyalty to her grandson. There however appears to have been no strong opposition to Ashurbanipal's rise to power. Shamash-shum-ukin was somewhat belatedly crowned as king of Babylon in the spring of the next year. His coronation was marked by Ashurbanipal returning the religiously important Statue of Marduk, stolen by Sennacherib twenty years prior, to Babylon. Shamash-shum-ukin would rule at Babylon for sixteen years, apparently mostly peacefully in regard to his younger brother, but there would be repeated disagreements on the exact extent of his control. Treaties drawn up by Esarhaddon are somewhat unclear as to the relationship he intended his two sons to have. It is clear that Ashurbanipal was the primary heir to the empire and that Shamash-shum-ukin was to swear him an oath of allegiance but other parts also specify that Ashurbanipal was not to interfere in Shamash-shum-ukin's affairs, indicating an intent for a more equal standing between them. Though it is possible that Ashurbanipal intentionally ignored Esarhaddon's wishes and shifted the balance of power in his own favor by diminishing Shamash-shum-ukin's intended status, such a decision might have been primarily motivated by Ashurbanipal fearing that granting his older brother a strong power-base would present a threat to his own continued rule. Military campaigns Egyptian campaigns Egypt was conquered in 671 by Ashurbanipal's father Esarhaddon, who defeated the Kushite Pharaoh Taharqa. The conquest of Egypt was one of Esarhaddon's greatest accomplishments, the first time Egypt had ever been under Assyrian rule, and brought the Assyrian Empire to its greatest extent. Assyrian control of Egypt was weak, however, and Taharqa escaped to Nubia in the south, scheming to retake his lands. Esarhaddon sent troops to garrison Egyptian cities and appointed local Egyptian nobles as vassal rulers of the country. In 669, Taharqa reappeared from the south and led Egypt in a revolt against Assyria. Esarhaddon left Nineveh to defeat Taharqa but fell ill and died on the way. Esarhaddon's death and the lack of an Assyrian response