From surnamedb.com
SEBERT (Saxon King)
"This interesting and unusual surname, with variant spellings Seabert, Sebright, Seebright, Sawbridge etc., derives from the Old English pre 7th Century personal name Saebeorht, a
compound of the elements "sae", sea, plus "beorht", bright. This personal name was borne by a 7th Century King of Essex, and is occasionally found on record until the 10th Century. It re-emerges as "Sebertus" in the "Pipe Rolls of Gloucestershire", dated 1199. One, Ricardus filius (son of) Sebriht was noted in the "Pipe Rolls of leicestershire", dated 1200. The surname first appears in the latter part of the 13th Century, (see below). Other early recordings include Peter Sabright, ("The Close Rolls of Essex", 1290) and Michael Sebryth, ("The subsidy Rolls of Suffolk", 1327). one, William Sebright".
Other unverified references to Sebert (or other spelling) mention legends of this king in relation to St. Columba, other early christian missions and sites that later became abbeys. Will need to dig deeper.
