Martin P. Nilsson's A History of Greek Religion is a comprehensive work tracing the evolution of Greek religion from the Minoan-Mycenaean period to its decline. It examines the origins of mythology, primitive rituals, the gods, the transition from Homeric anthropomorphism to rationalism, legalism, mysticism, and the differences between educated and peasant civic religion. It provides a comprehensive overview of how ancient Greek religion changed over time, influenced by cultural and social factors.