William Strauss and Neil Howe in their books 'Generations' and The Fourth Turning divide Anglo-American history into saecula, or seasonal cycles of history, and divide the saecula into generations by birth year, and classify generations and historical periods into four types each.

As history molds generations, so do generations mold history. Modern Anglo-American history runs on a two-stroke rhythm. The two strokes are an Awakening and a Crisis.

A High is an era between a Crisis and an Awakening, and an Unraveling is an era between an Awakening and a Crisis.

The four types of generations are as follows:

  • A Prophet (or Idealist) generation is born during a High, spends its rising adult years during an Awakening, spends midlife during an Unraveling, and spends old age in a Crisis. Prophetic leaders have been cerebral and principled, summoners of human sacrifice, wagers of righteous wars. Early in life, few saw combat in uniform; late in life, most come to be revered as much for their words as for their deeds.

  • A Nomad (or Reactive) generation is born during an Awakening, spends its rising adult years during an Unraveling, spends midlife during a Crisis, and spends old age in a new High. Nomadic leaders have been cunning, hard-to-fool realists, taciturn warriors who prefer to meet problems and adversaries one-on-one.

  • A Hero (or Civic) generation is born during an Unraveling, spends its rising adult years during a Crisis, spends midlife during a High, and spends old age in an Awakening. Heroic leaders have been vigorous and rational institution-builders, busy and competent in old age. All of them entering midlife were aggressive advocates of technological progress, economic prosperity, social harmony, and public optimism.

  • An Artist (or Adaptive) generation is born during a Crisis, spends its rising adult years in a new High, spends midlife in an Awakening, and spends old age in an Unraveling. Artistic leaders have been advocates of fairness and the politics of inclusion, irrepressible in the wake of failure.

The list of generations and their types is as follows:

      

GENERATION                                     TYPE           BIRTH YEARS                                    
Late Medieval Saeculum:
ArthurianHero1433-1460
HumanistArtist1461-1482
Reformation Saeculum:
ReformationProphet1483-1511
ReprisalNomad1512-1540
ElizabethanHero1541-1565
ParliamentarianArtist1566-1587
New World Saeculum:
PuritanProphet1588-1617
CavalierNomad1618-1647
GloriousHero1648-1673
EnlightenmentArtist1674-1700
Revolutionary Saeculum:
AwakeningProphet1701-1723
LibertyNomad1724-1741
RepublicanHero1742-1766
CompromiseArtist1767-1791
Civil War Saeculum:
TranscendentalProphet1792-1821
GildedNomad1822-1842
ProgressiveArtist1843-1859
Great Power Saeculum:
MissionaryProphet1860-1882
LostNomad1883-1900
G.IHero1901-1924
SilentArtist1925-1942
Millennial Saeculum:
BoomProphet1943-1960
13thNomad1961-1981
MillennialHero?1982-2003?
According to the above chart, generational types have appeared in Anglo-American history in a fixed order for more than 500 years, with one hiccup in the Civil War Saeculum. (The reasons for this is because according to the chart, the Civil War came about ten years too early; the adult generations allowed the worst aspects of their generational personalities to come through; and the Progressives grew up scarred rather than ennobled.)