We all know Sir Ian McKellen from the Lord of the Rings and X-Men movies, as well as for his warm and witty banter on The Graham Norton Show. Ahead of his appearance on this week's episode, in which he discusses his new movie The Good Liar, here are some things you might not know about the incredibly well respected thesp.

1. He co-founded Stonewall, now the U.K.'s leading LGBT rights charity.

The lobbying organization was actually conceived at Sir Ian's dining table in 1989, when he and a group of fellow activists realized they needed to campaign for the repeal of Section 28, a piece of legislation which prohibited the "promotion" of homosexuality in British schools. “We formed a lobby to change Section 28 and get rid of it,” Sir Ian recalled earlier this year. “We were doing something that we knew had to be done at some point. We were fighting not on our own behalf, but also on behalf of kids.” Section 28 was eventually repealed in Scotland in 2000, and in the rest of the U.K. in 2003.

2. He turned down the opportunity to play Dumbledore in the final six Harry Potter movies.

When original Dumbledore actor Richard Harris died in 2002, Sir Ian was approached to replace him. However, he declined because Harris had described him as a "technically brilliant, but passionless" actor. "I couldn’t take over the part from an actor who I’d known didn’t approve of me," Sir Ian told Variety in 2017.

3. He returned a rumored £1 million ($1.3 million) advance to write his memoirs.

"I put nine months aside to do it, and I got a very handsome advance. Then I sent the money back," Sir Ian told an audience at the Oxford Literary Festival in 2016. "It was a bit painful. I didn't want to go back into my life and imagine things that I hadn't understood so far. The privacy of my life I don't quite understand myself, and it has nothing to do with what I do for a living. So there you go, I'm sorry."

4. He became an ordained minister of the Universal Life Church in 2013.

Specifically so he could marry his great friend Sir Patrick Stewart and fiancée Sunny Ozell. Friendship goals.

5. He's a firm pescatarian who hasn't eaten meat since 1980.

Recalling the day he gave up eating meat, Sir Ian writes on his website: "I looked down from my terrace hanging over the Thames one morning. It was low tide and there, stranded on the pebbles, was a four-legged corpse - hairless, white, and bloated. Was it a calf or a sheep or a goat or a dog? I stared at it until the tide rose and washed it away. For 24 hours I was off my food. When I started eating again, I couldn't face meat -- fresh or tinned."

6. He has several nicknames – including Serena.

"Serena was wittily coined by Stephen Fry at a gay fundraiser," Sir Ian told The Independent a few years ago. "Others favour [calling me] Damian. In the U.S., impressed and unused to titles, I am invariably Sir McKellen. Computers address me as Siri McKellen. I answer to all."

7. He's appeared in several music videos, including the Pet Shop Boys' "Heart."

Sir Ian plays a vampire – check it out below.

https://www.youtube.com/watch?v=wTkfK2g4pKI

8. His great-great-grandfather helped to invent the weekend.

Yes, really! Documents from 1843 show that Sir Ian's ancestor Robert Lowes campaigned successfully for business owners in Manchester to allow their workers to take a half-day on Saturdays, giving them more than one day off for the first time. An expert on Sir Ian's episode of Who Do You Think You Are said of the actor's relative: “He can be viewed as the grandfather of the modern weekend.”

9. He took a few "souvenirs" from the Lord of the Rings set.

"And I think my favorite set, that I didn't act in, was the golden lair, where the dragon was hiding," Sir Ian told fans in his Reddit AMA. "[There were] hundreds of thousands of golden coins, specially made. And if you don't tell anyone, I can tell you that I have some of those coins. Along with the font door key to Bag End, which I know Peter Jackson is looking for, but will never find."

10. He co-owns a historic 16th century pub called The Grapes in east London.

Check out its website here. On this week's episode of The Graham Norton Show, airing Friday at 11/10c on BBC America, Sir Ian discusses how she sometimes moonlights as the pub's Monday night quiz master.

https://twitter.com/IanMcKellen/status/874267658320920577?s=20

What is your favorite Sir Ian McKellen role?