Wikipedia
Lloegyr is the medieval Welsh name for that part of Britain south and east of a line extending from the Humber Estuary to the Severn Estuary, exclusive of Cornwall and Devon. The people of Lloegyr were called Lloegyrwys without distinction of ethnicity, the term applying to both Britons and Anglo-Saxons.
The modern form of the word is Lloegr ( or ) and it has become generalised through the passage of time to become the Welsh word for "England" as a whole, and not restricted to its original, smaller extent. The word has been anglicised and Latinised into such forms as Logres, Logris, and Loegria, among others, and is perhaps most widely recognised as the name of King Arthur's realm in the body of literature known as the Matter of Britain. The word is known to date from the 10th century or earlier, as it appears in the literary Armes Prydein.