Plan B: Corporal Punishment - S4-E2
Blackadder: I remember Massingbird's most famous case - the Case of the Bloody Knife. A man was found next to a murdered body. He had the knife in his hand, thirteen witnesses had seen him stab the victim and when the police arrived he said 'I'm glad I killed the bastard.' Massingbird not only got him off, he got hom knighted in the New Year's Honours list, and the relatives of the victim had to pay to get the blood washed out of his jacket.
Plan B: Corporal Punishment - S4-E2
[Baldrick is called to the stand to defend Blackadder.]
Blackadder: Deny everything, Baldrick.
Lieutenant George: Are you Private Baldrick?
Baldrick: No.
Lieutenant George: But you are Captain Blackadder's batman?
Baldrick: No.
Lieutenant George: Come on, Baldrick. Be a little more helpful. It's me.
Baldrick: No, it isn't.
Answer: The closest we ever get to knowing his first name is in series 3, when he claims it's "Sod Off". Blackadder asks him in series 3 where this came from, and he replies "Well, when I was a kid, living in the gutter, I'd go up to the other kids and say 'Hello, I'm Baldrick'. And they'd say, 'Yes, we know. Sod off, Baldrick.'" The S in this series is likely a reference to that, but it's not addressed, and given this Baldrick is clearly different from the series 3 Baldrick, we can't draw a direct link.
Shay