The Fourth Turning is a conceptual framework developed by William Strauss and Neil Howe, suggesting that history unfolds in a recurring four-phase cycle or 'turning' which typically spans roughly 80-100 years. According to their theory, each cycle consists of a High, an Awakening, an Unraveling, and a Crisis, with the Fourth Turning representing the period of Crisis where society undergoes transformative change leading to the birth of a new order.