Heath Ledger — who enters leading-man territory this Friday with the opening of A Knight's Tale — says he's not surprised that Hollywood's A-list is being overthrown by Down Underlings. "[It's a] secret invasion," he jokes to TV Guide Online, referring to fellow Aussies

Mel Gibson, Russell Crowe and Hugh Jackman. "We sent some spies over 10 years ago and they set it all up for us."

But seriously, Ledger, whose career got a major boost with last summer's Gibson-starring epic The Patriot, insists that it was never his decision to become a major celeb. "I've always been an actor — I'm being created into a star," says the 22-year-old thesp. "That's the studio's decision."

Another mandate from Columbia suits: Ledger was not allowed to engage in combat for his role as a medieval jouster in A Knight's Tale. "I didn't get hit," he admits. "They wouldn't let me ride a bicycle — insurance-wise — let alone get hit by a guy charging at me in armor."

Tale still claimed its share of casualties — only the mishaps occurred after filming wrapped. While demonstrating a combat move during post-production, Ledger accidentally knocked out director Brian Helgeland's front tooth. And if that wasn't enough, "My knee was busted because I slipped like an idiot in the editing lounge," marvels Ledger. "I was sliding on the floor and went up in the air and landed on my knee. I could barely walk."

These days, the 10 Things I Hate About You star is keeping himself grounded, despite his newfound fame. What's his secret? "You don't believe anything you read — good or bad," he offers. "Especially good."