Logres

Logres (also Logris or Loegria) is King Arthur's realm in the Matter of Britain. It derives from the medieval Welsh word Lloegyr, a name of uncertain origin referring to England (Lloegr in modern Welsh).

In Arthurian contexts, "Logres" is often used to describe the Brittonic territory roughly corresponding to the borders of England before the area was taken by the Anglo-Saxons. According to Geoffrey of Monmouth's influential pseudohistory Historia Regum Britanniae, the realm was named after the legendary king Locrinus, the oldest son of Brutus of Troy. In his Historia, Geoffrey uses the word "Loegria" to describe a province containing most of England excluding Cornwall and possibly Northumberland, as in this example from section iv.20 (from the Puffin Classics translation by Lewis Thorpe):

Parishes were apportioned off, Deira being placed under the Metropolitan of York, along with Albany, for the great River Humber divides these two from Loegria. Loegria itself was placed under the Metropolitan of London, along with Cornwall. The Severn divides these last two provinces from Kambria or Wales, which last was placed under the City of Legions.[1]

The name "Logres" is used in many works of modern fantasy set in Britain, for example, C. S. Lewis's That Hideous Strength and Susan Cooper's Over Sea, Under Stone.