Cornish surnames for ordinary people emerge in the Middle Ages, although the nobility probably had surnames much earlier on.
The most common surnames in Cornwall are patronymics. The fatherís first name being taken without alteration and a genitive Ďsí added. eg. John (of) Typically Cornish was the addition of an "o" for example in the surname Bennetto or a "y" as in the surname "Pawley".
Meaning of surname Bolster: Bolla, a casting or throwing up, and ter, the earth