Etymology of London: From Londinium to Modern Name

How London Got Its Name

London's name has evolved over two millennia, with roots in pre-Roman Britain and layers of linguistic transformation.

Roman Foundation: Londinium (c. 43–50 AD)

The Romans established a trading settlement on the Thames' north bank, naming it Londinium. This wasn't a Latin word but a Romanization of a pre-existing Brittonic place-name.

Pre-Roman Origins: Brittonic *Londinion

Linguists reconstruct the original as *Londinion or *Londinjon, likely from:

• *lond- — possibly "wild, forested" or a personal name *Londinos
• *-injon/-inion — suffix meaning "place of" or "settlement of"

Alternative theory: *Llyn Dain (Welsh) → "lake fort" or "pool fortress," referencing the Thames' tidal marshes or the Walbrook stream.

Medieval Evolution

• Anglo-Saxon: Lundenwic (trading settlement west of Roman walls, 7th c.), later Lundenburh (refortified City, 9th c.)
• Norman: Lundres, Londres (Domesday Book 1086)
• Middle English: London, Londoun, Lundon
• Modern: Standardized as London by 15th century

Debunked Theories

• "Lundinia = place of the moon" — false Latin back-formation; no Celtic lunar deity *Lundinos attested
• King Lud — Geoffrey of Monmouth's legendary founder (12th c. fiction)

River Names as Clues

The Thames (Tamesis) and its tributaries (Fleet, Walbrook, Tyburn) carry Brittonic names, confirming dense pre-Roman habitation. Londinium likely designated a specific ford or trading node, not the whole valley.

Consensus: London = Romanized Brittonic *Londinion, "place at the navigable river/ford," possibly referencing the tidal Thames' highest practical crossing point.