Saintly Simon, a historic knight (7)

I believe the answer is:

templar

I'm a little stuck... Click here to teach me more about this clue!

'knight' is the definition.
(I know that Templar is a type of knight)

I don't understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for templar that I've seen before include "Lawyer" , "Knight of a religious and military order" , "barrister" , "Simon - (The Saint)" , "Member of religious and military order" .)

I've seen this clue in the Evening Standard.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.