I can picture the man but can’t for the life of me remember what he’s been in.

He’s a British actor with white hair. Looks a bit like a scruffy Ian McKellen. You’d certainly lump him in with Gambon, McKellen, etc. That age.

Any ideas?

The Gambon?

EDIT: Damn your stealth edit – I thought I’d won. 😳

Not Bill Nighy?

John Hurt, what’s the prize?

Brian Cox

…or maybe it’s Saruman, not Gandalf…

None of them. Bit Gambon-ey.

White crazy hair. Sticks out to the sides.

Damn, there’s just no pleasing some people.

Okay, hair sticking out at the sides then… maybe…

You didn’t say if they were alive or dead so I shall go with the latter and suggest,
Richard Harris

peter o’toole ?

Bill Nighy?
I dunno – take your pick?

Richard Harris?

John Hurt

Ian McKellen?