History

July and August

Quintilis and Sextilis, before the Caesars moved in
Two men own a sixth of your year. They are the only months named for human beings, and both were granted, not taken: one for the murdered Caesar, one for his heir who finished the war.
Documented

The Senate's receipts

Both renamings are in the primary record. Macrobius, Saturnalia 1.12, preserves the decrees: Quintilis became Iulius in 44 BC because Caesar was born in it; Sextilis became Augustus by senatorial decree in 8 BC. Suetonius, Augustus 31, gives the stated reasons: in that month he first entered the consulship and won his greatest victories, Egypt among them. The month you call August is, on paper, a war memorial.

Assessment: This is documented twice over and uncontested. Your summer is a triumphal inscription that outlasted every arch Rome built.
Stories

The stolen day

Everyone knows the story: July had 31 days, so Augustus took one from February to keep his month from being shorter, and that is why February limps. It is a perfect little tyrant anecdote, and it is not in any Roman source. Macrobius' account of the calendar has the month lengths fixed before the renaming; the story of the theft surfaces in medieval computus handbooks, a thousand years late.

Assessment: A debunk with a clean signature: the anecdote flatters our sense of imperial vanity precisely because it is the kind of thing an emperor would do. Augustus needed no theft; the Senate had already given him the sky.
Interesting claims

The month that ate a kingdom

Of all months, the Senate chose Sextilis because it held the climax: Alexandria fell on the first of it in 30 BC, Antony and Cleopatra died, and the last Hellenistic kingdom became a Roman province. August is not named for a man's birthday; it is named for the month the republic's long war actually ended. Every August you write on a form is a dated anniversary of the annexation of Egypt.

Assessment: The motive is stated in the sources themselves, which makes this the rare imperial vanity project with its own documentation. Two millennia of calendars have kept the war trophy polished.
Sources and further reading
  1. Macrobius, Saturnalia 1.12.34-35, Quintilis becomes Iulius, Sextilis becomes Augustus
  2. Suetonius, Augustus 31, the Senate's stated reasons, first consulship and Egypt
  3. Dio Cassius 55.6, the renaming debate of 8 BC
  4. The medieval computus handbooks, first attestation of the stolen-day story
  5. Appian, Civil Wars, Alexandria's fall on August 1, 30 BC
Worth asking

Every emperor after them wanted a month and nearly all failed. What does it say that the only two names still on your calendar belong to the men who never had to rename it themselves?

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GR8YFILES · competing origin stories, labeled by the strength of their evidence · readers 14+