In a GQ video posted Monday, actor Gerard Butler explains when he screamed the iconic ‘300’ line “This is Sparta!” that his army almost broke character laughing.

Gerard Butler Screaming "This Is Sparta!" Made '300' Cast Laugh

 

It has become one of the more iconic lines in film history — and it was a complete surprise to everyone on set. In a GQ video posted Monday, Gerard Butler discussed a number of characters he has played throughout his career. Of course, Leonidas, King of Sparta from 300 (2007), was on the list.

The actor revealed how he lobbied hard for the part and worked out every day, but the most interesting aspect was the tale behind that one line: “This is Sparta!”

Explained Butler, “I had done quite a few takes and most of them were ‘This is Sparta,’” said in a low, monotone growl. “And it’s part process and part insecurity, maybe. And I go, ‘Can I just try another?’”

The next take would be the (often-imitated) scream from director Zack Snyder’s film.

“And I turn around and all my army are literally like this,” he said with a hand over his mouth hiding laughter. “And I go up to Zack and I go, ‘That was too much?’ And he goes, ‘Yeah! But it was awesome!’”

The film 300 would go on to be a big hit, grossing $456 million worldwide on a $65 million budget. Butler currently starrs in Angel Has Fallen, the third installment in the Fallen series, which debuted at No. 1 with $21 million at the North American box office over the weekend.

Watch Butler’s GQ video below.