He was a great West Country landowner and apparently a close advisor[1] of his son-in-law Edgar the Peaceful, king of England.
The Oxford Dictionary of National Biography draws a conclusion that Ordgar was "clearly a figure of some importance" to have secured such a match.
[1] King Edgar determined on marrying Ælfthryth and to this end he sent Æthelwald, Ealdorman of East Anglia as his agent to woo her.
On arrival Æthelwald found her in company with her father Ordgar, whom she completely controlled by her personality, playing chess, which they had learned from the Danes.
It is, however, certain that, under whatever actual circumstances, Ælfthryth became King Edgar's third wife in 964 and in the same year her father Ordgar was created ealdorman.