The two men began feuding after Russell accused George of being "a sellout" during an interview with GQ.
Russell Crowe had questioned the American star's decision to appear in adverts for things like coffee, insisting it was a bad use of his celebrity.
A war of words ensued and it was then reported that Australian star Russell had said sorry, reportedly after realising the two might see each other during an awards season.
"The truth is that [Crowe] did send me a book of poems to apologise for insulting the sh*t out of me, which he did. He picked a fight with me. He started it for no reason at all. He put out this thing saying, ‘George Clooney, Harrison Ford, and Robert De Niro are sellouts,’" George confirmed to US Esquire magazine.
In retaliation George poked fun at Russell's band 30 Odd Foot of Grunts, which didn't go down well with the actor.
"That’s when he really went off on me. ‘Who the f**k does this guy think he is? He’s a Frank Sinatra wannabe.’ He really went after me," he said.
"But then I had a year. Then I had Syriana and Good Night, and Good Luck, and he was gonna see me at the Golden Globes ’cause he was nominated for Cinderella Man. So he sends me a disc of his music and a thing of his poetry. I think he said, ‘I was all misquoted,’ and I was like, ‘Yeah, yeah. Whatever.’"
Russell wasn't the only star George was happy to chat about. He also gave his opinion on Leonardo DiCaprio, who he has concerns about. The pair once played a game of basketball, which Leonardo's friends almost ruined with their smack talk.
"And the discrepancy between their game and how they talked about their game made me think of how important it is to have someone in your life to tell you what's what," George explained. "
"I'm not sure if Leo has someone like that."
George also gave his opinion on social networking sites, claiming he can see no reason why celebrities use Twitter. His good friend Brad Pitt doesn't use the site, which George thinks makes him seem less available and so more interesting.
The 52-year-old star also worries Twitter can have a damaging effect.
"If you’re famous, I don’t - for the life of me - I don’t understand why any famous person would ever be on Twitter. Why on God’s green earth would you be on Twitter? Because first of all, the worst thing you can do is make yourself more available, right? Because you’re going to be available to everybody. But also Twitter. So one drunken night, you come home and you’ve had two too many drinks and you’re watching TV and somebody p**ses you off, and you go, ‘Ehhhhh,’ and fight back," he explained. “And you go to sleep, and you wake up in the morning and your career is over. Or you’re an a*shole."