Quote Originally Posted by Laird O'the Cowcaddens View Post
Not sure I agree with the oldest Regt answer, I believe it to be The Royal Scots(1st Bn RRS) also known as Caesar's bodyguard. I believe the answer to the Mercenary question is the Gurkha.
The Royal Scots date back to 1633, but they are not continuously serving, as are the Coldstream Guards. I'm pretty sure that it was the Royal Scots who were known as "Pontius Pilate's Bodyguard", but there are probably other regiments who've made the claim.