Osorkon ruled during one of the most chaotic and politically fragmented periods of ancient Egypt, in which the Nile Delta was dotted with small Libyan kingdoms and principalities and "Meshwesh" dominions; as the last heir of the Tanite rulers, he inherited the easternmost parts of these kingdoms, the most involved in all the political and military upheavals that soon would afflict the Near East. During his reign, he had to face the power, and ultimately submit himself—to the Kushite King Piye during Piye's conquest of Egypt. Osorkon IV also had to deal with the threatening Neo-Assyrian Empire outside his eastern borders.