Next to nothing seems to be known about Sir Tegyr, yet he seems to have been thought important enough to be included - as Sir Degore - amongst the twenty-five Knights listed on the Winchester Round Table. He appears as King Arthur's cup-bearer in the tale of Culhwch & Olwen. 

A Sir Degore is the subject of a Middle English romance of the same name, but he had nothing to do with King Arthur. This form of the name has probably been influenced by the epithet of Sir Uriens de Gore, the historical King of Rheged alias Gore (Cumbria) and King Arthur’s brother-in-law.