Etymograph

English

brethren

Brethren comes from Old English brōþor ‘brothers, brethren’, and goes back to Proto-Indo-European *bʰréh₂tēr.

  1. Proto-Indo-Europeanc. 4500–2500 BCE*bʰréh₂tēr1‘brother’reconstructed
  2. Proto-Germanicc. 500 BCE–200 CE*brōþēr2‘brother’reconstructed
  3. Proto-West Germanicc. 200–500 CE*brōþer3‘brother’reconstructed
  4. Old Englishc. 450–1150brōþor4‘brothers, brethren’
  5. Middle Englishc. 1150–1500brethere4
  6. Middle Englishc. 1150–1500brethren4
  7. Englishearliest quotation 1863brethren4

attested reconstructed ? uncertain or disputed deepest recorded ancestor

  1. 1 Wiktionary, Proto-Germanic *brōþēr
  2. 2 Wiktionary, Proto-West Germanic *brōþer
  3. 3 Wiktionary, Old English broþor
  4. 4 Wiktionary, English brethren
  5. Earliest quotation in Wiktionary’s entry: 1863, Jules Michelet: “The Introit over, the service is interrupted for the…”.

Lineage

  1. Proto-Indo-Europeanc. 4500–2500 BCE*bʰréh₂tērWiktionary, Proto-Germanic *brōþēr‘brother’reconstructed
  2. Proto-Germanicc. 500 BCE–200 CE*brōþērWiktionary, Proto-West Germanic *brōþer‘brother’reconstructed
  3. Proto-West Germanicc. 200–500 CE*brōþerWiktionary, Old English broþor‘brother’reconstructed
  4. Old Englishc. 450–1150brōþorWiktionary, English brethren‘brothers, brethren’
  5. Middle Englishc. 1150–1500brethereWiktionary, English brethren
  6. Middle Englishc. 1150–1500brethrenWiktionary, English brethren
  7. Englishearliest quotation 1863brethrenWiktionary, English brethren. Earliest quotation in Wiktionary’s entry: 1863, Jules Michelet: “The Introit over, the service is interrupted for the…”

The story

Ultimately from Old English brōþor, brōþru (‘brothers, brethren’), influenced by Old English brēþer, dative singular of brōþor (‘brother’). The vowel change (from o to e) is called umlaut.

Full etymology on Wiktionary

Linked words

through Proto-Indo-European *bʰréh₂tēr ‘brother’

pal, fraternity, bhai, fra, fraternal, friar, frater, 11 more

through Old English brōþor ‘brothers, brethren’

brother, bro, 4 more

Today it means

noun kinsmen

Sources

Sources: Wiktionary, “brethren”; the older steps come from the Wiktionary entries for Proto-Germanic *brōþēr, Proto-West Germanic *brōþer, Old English broþor. By Wiktionary contributors, CC BY-SA 4.0, via kaikki.org (dump of Oct 3 2026); text adapted and restructured. Language periods are conventional ranges, not dates for this word. License.

Etymograph / Proto-Indo-European *bʰréh₂tēr / brethren

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