Disputed Statements

The Gilded Age, Eras

Standing Scholarly debate

Concerns Start Year

Currently States 1877

Conventionally dated from the late 1870s, often anchored to the end of Reconstruction in 1877; historians vary on the exact starting point.

The Gilded Age, Eras

Standing Scholarly debate

Concerns End Year

Currently States 1896

Conventionally closed in the late 1890s, sometimes extended to the 1900 election; historians vary on the exact end point.

The Great Zimbabwe Period, Eras

Standing Scholarly debate

Concerns Start Year

Currently States 1220

Sources date the rise to capital status only to the century, the 13th; 1220 is used as a representative year within it.

Source Wikipedia: Great Zimbabwe tier 2

The Great Zimbabwe Period, Eras

Standing Scholarly debate

Concerns End Year

Currently States 1450

Major stone construction ran from the 11th to 15th centuries and the site was not fully abandoned until the 16th or 17th century; 1450 marks the end of the kingdom's major building and imperial power rather than final abandonment.

Source Wikipedia: Great Zimbabwe tier 2

The Gupta Empire, Polities

Standing Scholarly debate

Concerns Capital

Currently States Pataliputra (reputed; disputed among historians)

Sources call Pataliputra the dynasty's reputed capital, but historians dispute whether it was in fact the Gupta capital, and even the dynasty's own homeland region is uncertain.

Source Wikipedia: Gupta Empire tier 2

The Gupta Empire, Polities

Standing Scholarly debate

Concerns Start Year

Currently States 250

The empire's own lead dating is century level, mid third to mid sixth century CE; 250 and 550 are representative years within those centuries, not exact founding or end dates (matching the dating convention already used on the sibling Gupta Golden Age era entity, 270883).

Source Wikipedia: Gupta Empire tier 2

The Gupta Empire, Polities

Standing Scholarly debate

Concerns End Year

Currently States 550

The empire's own lead dating is century level, mid third to mid sixth century CE; 250 and 550 are representative years within those centuries, not exact founding or end dates (matching the dating convention already used on the sibling Gupta Golden Age era entity, 270883).

Source Wikipedia: Gupta Empire tier 2

The Gupta Golden Age, Eras

Standing Scholarly debate

Concerns Start Year

Currently States 250

The empire's own lead dating is century level, mid third to mid sixth century CE; 250 and 550 are representative years within those centuries, not exact founding or end dates.

Source Wikipedia: Gupta Empire tier 2

The Gupta Golden Age, Eras

Standing Scholarly debate

Concerns End Year

Currently States 550

The empire's own lead dating is century level, mid third to mid sixth century CE; 250 and 550 are representative years within those centuries, not exact founding or end dates.

Source Wikipedia: Gupta Empire tier 2

The Hellenistic Period, Eras

Standing Scholarly debate

Concerns End Year

Currently States -30

Scholars are divided on which event should mark the Hellenistic period's end. The atlas follows the majority convention of 30 BCE (the Battle of Actium and the Roman annexation of Ptolemaic Egypt under Cleopatra VII and Mark Antony's defeat), but the literature proposes alternative endpoints ranging from 146 BCE (Rome's conquest of the Greek mainland) at the early end to 330 CE (Constantine's founding of Constantinople) at the late end, reflecting genuine disagreement about how long Hellenistic political, cultural and religious forms continued to shape the eastern Mediterranean after Rome's conquest of Egypt.

Source Wikipedia: Hellenistic Period tier 2

The Hundred Years' War, Events

Standing Scholarly debate

Concerns Death Toll, Low Estimate

Currently States 2300000.000000

Rough order-of-magnitude estimate for direct and indirect (famine, associated violence) deaths across the war's 116 years (1337-1453), per general military-historical demography; medieval record-keeping cannot isolate war deaths cleanly from the concurrent Black Death and recurring regional famine, so this range is treated as illustrative rather than precise.

Source Edward III (Britannica)

The Hundred Years' War, Events

Standing Scholarly debate

Concerns Death Toll, High Estimate

Currently States 3300000.000000

Upper bound of the same rough estimate; see death-toll-min's StatusNote on why this range is not precise.

Source Edward III (Britannica)

The Industrial Revolution, Events

Standing Scholarly debate

Concerns Year

Currently States 1760

There is no single starting date. Historians commonly place the beginning of industrialization in Britain somewhere between 1760 and 1780, and its spread to other countries occurred at very different times across the following century.

Source The New Cambridge Modern History

The Invention of Writing, Events

Standing Scholarly debate

Concerns Year

Currently States -3200

Sumerian cuneiform, the earliest securely dated writing system, emerges around 3200 BCE, but writing was invented independently in Egypt around 3100 BCE, in China around 1200 BCE and in Mesoamerica later still, so no single year marks the invention of writing worldwide.

Source Encyclopaedia Britannica

The Iron Age, Eras

Standing Scholarly debate

Concerns Start Year

Currently States -1200

The general date, c. 1200 BCE, describes the eastern Mediterranean and Near East; the transition to iron began earlier, around 1300 BCE, in Anatolia and the Caucasus, and far later, around 500 BCE, in Northern Europe.

Source Wikipedia tier 2

The Iron Age, Eras

Standing Scholarly debate

Concerns End Year

Currently States -550

The general date, c. 550 BCE, describes the eastern Mediterranean and Near East; the transition to iron happened at markedly different times elsewhere, from as early as 1300 BCE in Anatolia to as late as 500 BCE in Northern Europe.

Source Wikipedia tier 2

The Khmer Empire, Polities

Standing Scholarly debate

Concerns End Year

Currently States 1431

Historians differ on why the Khmer Empire declined: proposed causes include the ideological shift from the Hindu devaraja cult to Theravada Buddhism, repeated military pressure from the Ayutthaya Kingdom between 1352 and 1431, and environmental stress from a period of severe drought following intense monsoon rains that damaged the empire's canal and reservoir network. The atlas records 1431, the fall of Angkor to Ayutthaya, as the conventional end date.

Source Wikipedia: Khmer Empire tier 2

The Kingdom of England, Polities

Standing Scholarly debate

Concerns Start Year

Currently States 927

927 marks Aethelstan's submission of the northern rulers and his assumption of the title king of the English, the conventional date for a unified Kingdom of England. Some historians place genuine, lasting unification later, under Edgar (959 to 975) or at the Norman Conquest of 1066.

Source England (Britannica)

The Kingdom of France, Polities

Standing Scholarly debate

Concerns Start Year

Currently States 987

Marks Hugh Capet's election as king of the Franks. Some historians read this as dynastic continuity from the Robertian family's existing power rather than a sharp break with Carolingian rule; 987 is nonetheless the conventional founding date for the Capetian kingdom.

Source France: History (Britannica)

The Kingdom of France, Polities

Standing Scholarly debate

Concerns End Year

Currently States 1789

Marks the Revolution's outbreak as the effective end of the ancien regime kingdom. The absolute monarchy was not formally abolished until 21 September 1792, when the National Convention proclaimed the First Republic; this entity uses 1789 to mark the polity's defining end point, with the intervening constitutional monarchy (1789 to 1792) as the transition. See the edge to The French Revolution.

Source France: History (Britannica)