In four years, Justin Bieber has ascended from a talented young Canadian singer to an international pop sensation. As he now turns 19 years old today, we take a look back at the evolution of the music sensation as seen through ET's lens.
It all began in 2007 when music executive and Bieber's eventual manager Scooter Braun stumbled upon his YouTube videos and soon after signed him to Raymond Braun Media Group, owned by Braun and Usher.
Although he had gained immense fame in the internet world, Bieber was still relatively unknown until he released his first single, "One Time," in May 2009. A few months before then, he got a sample of the many things that would come with his future fame when he attended the Kids Choice Awards with Usher.
PICS: Justin Bieber Celebrates His Birthday Shirtless
It didn't take long for the then-15-year-old singer to catch traction in the industry. Bieber's first single landed at No. 17 on American charts and No. 12 in his native Canada. Moreover, he became an instant heartthrob for teenage girls.
"I mean, I'm ready as I'll ever be," Bieber says after filming his first music video when asked if he's ready for the attention. "It's already started."
After he released an EP in 2009, Bieber re-released it with a few additional tracks, including the hit single "Baby," as his debut album, My World 2.0. It topped the charts around the world and peaked at No. 1 in both his native Canada and the U.S.
Since then, Bieber hasn't looked back.
VIDEO: Justin Bieber Spills Tour Secrets
After making his first world tour, he followed My World 2.0 with a Christmas album, Under the Mistletoe, which again thrived and achieved triple-platinum certification in Canada just as his debut album had.
Unfortunately for the young pop star, his success, like many other celebrities', hasn't come without the drawbacks of fame. However, as Bieber has continued to grow underneath the microscope of public attention and paparazzi flashes, he still seems to preserve what's most important to him.
Bieber released his third album, Believe, this past summer. To the dismay of critics, he proved to successfully make the transition that came along with puberty. It was a new style for him, but it caught on.
VIDEO: Justin Bieber on Interacting with Hysterical Fans
Now on his second world tour, Bieber turned 19 in Birmingham, England today.
Bieber has had an extraordinary four years, but as bright as his star shines right now, there is still some skepticism that questions how much longer his star will burn bright.
"I think I've already got over that hump," Bieber said before his recent world tour. "...I think it's now about just making good music and keeping the fans in tune and...not becoming something that you're not; being true to myself always; being a good person because that's always going to keep my mom happy.
VIDEO: Justin Bieber Views Himself as the 'Underdog'
"...At the end of the day, if I'm walking around here like I'm...everything...I feel like that's when I'm going to start falling, so I always got to stay humble."