In 1997, the historians William Strauss and Neil Howe published The Fourth Turning, a book that describes and expands upon the generational theory of history for which the two authors are regarded. Strauss and Howe contend that all of a society’s history is divided into saecula, or roughly 88-year periods that span the length of a long human life. Within each saeculum lie four ordered eras, or “turnings,” that include a “high,” “awakening,” “unraveling” and “crisis,” after which point the cycle repeats and a new saeculum begins. A high is comprised by an era of good, or stable feelings and conditions. The awakening occurs when high-era ideals are challenged and replaced.