Name: Sir Robert Greene
First Appearance: The Brave and the Bold (vol. 1) #173 (Apr. 1981): "Knight's Gambit"
Number of Appearances: 2
Note: named after DC employee Robert Greenberger
The character of Sir Robert Greene was named after DC employee Robert Greenberger, who is Jewish. As far as we know, the religious affiliation of the character "Sir Robert Greene" is never actually addressed in this story.
Suggested links for further research about this character and the character's religious affiliation: