Hello, from Brittany.The name Lloegr (Logres), comes from LEGORENCIS CIVITAS, today Leicester.
That name comes from arthurian's legends.
as The " Blue Forest" is Lichfield / LETOCETUM / Lwytgwyd (from * liv-id = blue, pale, etc).
as the SORELOIS is today Sorehault, not far from Leicester.
All theses nemes are on the direction of North Wales (Nort-Galles in the Romans), from London.
Leicester have been the second capital for the Romano-Bristih after the fall of London (so after 525-530 P.C).
(Emgann Karaez. La Bataille de Carohaise. The Battle of Carohaise. Copyright JC Even. 1996)
Jean-Claude EVEN