The Middle Assyrian Empire, spanning from the accession of Ashur-uballit I around 1365 BCE to the death of Ashur-dan II in 912 BCE, represents a significant phase in Assyrian history. This era marked Assyria's emergence as a major empire, building on its earlier presence as a city-state with trading colonies in Anatolia and influence in Southern Mesopotamia since the 21st century BCE.

Under Ashur-uballit I, Assyria gained independence from the Mitanni kingdom and began to expand. Key figures in Assyria's rise to power included Adad-nirari I (circa 1305–1274 BCE), Shalmaneser I (circa 1273–1244 BCE), and Tukulti-Ninurta I (circa 1243–1207 BCE). These kings propelled Assyria to a dominant position in Mesopotamia and the Near East, surpassing rivals like the Hittites, Egyptians, Hurrians, Mitanni, Elamites, and Babylonians.

Tukulti-Ninurta I's reign represented the peak of the Middle Assyrian Empire, witnessing the subjugation of Babylonia and the establishment of the new capital, Kar-Tukulti-Ninurta. However, following his assassination around 1207 BCE, Assyria experienced inter-dynastic conflict and a decline in power, although it was relatively unaffected by the Late Bronze Age collapse.

Even during its decline, Middle Assyrian rulers like Ashur-dan I (circa 1178–1133 BCE) and Ashur-resh-ishi I (circa 1132–1115 BCE) remained active in military campaigns, particularly against Babylonia. A resurgence occurred under Tiglath-Pileser I (circa 1114–1076 BCE), who expanded Assyrian influence to the Mediterranean, the Caucasus, and the Arabian Peninsula. However, post-Tiglath-Pileser's son, Ashur-bel-kala (circa 1073–1056 BCE), the empire faced a more severe decline, losing most territories outside its core regions due to Aramean invasions.

Ashur-dan II's reign (circa 934–912 BCE) marked the beginning of a reversal in Assyrian fortunes. His extensive campaigns laid the groundwork for the transition to the Neo-Assyrian Empire, expanding beyond the empire's former boundaries.

Theologically, the Middle Assyrian period was crucial in the evolution of the deity Ashur. Initially a personification of the city of Assur, Ashur became equated with the Sumerian god Enlil, transitioning into a military deity due to Assyrian expansion and warfare.

Politically and administratively, the Middle Assyrian Empire saw significant changes. The transition from a city-state to an empire led to the development of sophisticated systems for administration, communication, and governance. Assyrian kings, previously titled iššiak ("governor") and ruling alongside a city assembly, became autocratic rulers with the title šar ("king"), reflecting their elevated status akin to other empire monarchs.