The author examines the religious beliefs, pantheon, and practices of ancient Babylonia and Assyria, drawing directly from archaeological discoveries and cuneiform inscriptions recovered from Mesopotamian mounds. The volume begins by surveying the primary sources available for the study, ranging from classical historians and biblical references to the nineteenth and twentieth-century excavations of ancient cities like Nineveh, Babylon, Nippur, and Lagash. The text explores the earliest phase of the Babylonian religion, characterized by animism and local nature cults, where each city maintained its own protecting deity. Detailed attention is given to the oldest known gods, including En-lil of Nippur, Ea of Eridu, Nergal of Cuthah, and the sun and moon deities, as well as the shadowy female consorts that accompanied them.
The narrative then shifts to the political unification under Hammurabi, which established the supremacy of Babylon and elevated its patron god Marduk to the head of the pantheon. The author explains how this political centralization forced a theological restructuring, merging older gods with Marduk and creating a unified triad of Anu, Bel, and Ea to govern the universe. Subsequent chapters explore the distinct characteristics of the Assyrian pantheon, the military and storm deities, and the literary traditions preserved in royal libraries like that of Ashurbanabal. The book concludes with an estimate of the religion's influence on the ancient world and its eventual decline under foreign conquests.