In a relatively short span, Canadian phenom Justin Bieber has gone from earnest mop-topped teen busker to influential, chart-topping international pop star.

Undoubtedly the most successful of the new generation of artists who found fame through homemade YouTube performance videos, the hardworking Bieber has become even busier since first garnering the attention of the music industry in 2008. To date, he's released seven albums (three studio, four compilations), a photo book/biography and a music film.

Friday marks the Stratford, Ont. performer's 19th birthday. As Bieber celebrates reaching the landmark age (reportedly with a lavish party in London, a brief break from his current tour), he faces a watershed moment of his career: making the transition from squeaky-clean pop upstart to credible adult artist whose appeal stretches beyond teenage girls.

CBC looks back at key moments of Bieber's remarkable career so far.

1. March 1, 1994: Justin Bieber is born to Patricia Lynn Mallette, 18, and Jeremy Jack Bieber,19.
2. 1998: A four-year-old Bieber begins to show a propensity for music. He starts banging on a kiddie drum set and takes music lessons. In subsequent years, he begins dabbling in piano, guitar and trumpet.
3. 2006: After entering a local singing contest in his hometown of Stratford, Ont., he places second with a cover of Ne-Yo’s So Sick. His mother records it for absent friends and uploads the footage to YouTube. After the video becomes a viral hit, Bieber adds more of him performing (memorable spots include busking on the steps of the Stratford Festival’s Avon Theatre).
4. Late 2007/early 2008: The online videos attract the attention of manager Scooter Braun, who was purportedly searching videos online for would-be stars.
5. 2008: Braun flies him to Atlanta to meet Usher, the former teen heartthrob-turned-established R&B star. Bieber moves to Atlanta in July and, by October, signs to Island Records.
6. November 2009: Bieber drops his first album, My World. Seven of its songs break into the Billboard Top 100 chart and the album goes platinum. That month, he also sparks his first fan-crush incident, with New York police forced to cancel an autograph session after some fans turn wild, unruly and dangerous while awaiting his arrival (significant trampling incidents would later occur in Australia, in 2010, and Oslo in 2012).
7. 2010: He ventures out on his first international tour, My World, with stops in Europe and Asia.
8. February 2010: Bieber becomes ubiquitous with the release of the video for his single Baby, which features guest appearances from fellow Canadian Drake as well as Southern rapper Ludacris. It becomes the most-watched YouTube video of all time (until it was unseated by Gangnam Style in late 2012). The hit track paves the way for the release of his album My World 2.0, released a month after the video.
9. October 2010: Bieber releases the biography and photo book First Step 2 Forever: My Story.
10. December 2010: Rumours surface about the singer's first high-profile romance: his courtship of teen actress-singer Selena Gomez (They would later part ways in November 2012).
11. Feb. 2011: He debuts the 3D music film Justin Bieber: Never Say Never, a documentary of his time on tour.
12. March 2011: Bieber wins his first Juno Award (picking up two trophies, in fact), after also having earned nominations for the Grammy Awards.
13. November 2011: The young singer faces his first major controversy when a paternity suit is filed in California by a woman who alleges that Bieber fathered her child during a backstage fling (when she was 19 and he was 16). The suit is dropped days later.
14. June 2012: Bieber draws an estimated 200,000 fans to a free concert at Mexico City’s Zocalo Square, joining such international stars as Paul McCartney and Shakira in attracting similarly sized audiences at the historic spot.
15. July 2012: Bieber graduates high school.
16. December 2012/January 2013: The holiday season and New Year would prove bizarrely eventful for the young star under constant glare: authorities release details of an alleged murder plot against him, a paparazzo is struck by a car and killed while trying to snag a photo of him and images of the singer emerge showing him smoking pot.
17. January 2013: Bieber overtakes Lady Gaga as the most-followed person on Twitter, with more than 33 million fans. The figure has since climbed past 35 million.
18. February 2013: A satisfying cap to his teen years, Bieber becomes the youngest artist to rack up five No. 1 albums.
19. Feb. 2013: Bieber joins a small group — including Elton John and Bruno Mars — to serve as both host and featured performer on longrunning TV sketch show Saturday Night Live.

Justin Bieber, seen on Late Night With Jimmy Fallon last month, turns 19 on Friday. He faces a key transition: progressing from teen pop phenom to credible adult artist with appeal beyond teen girls. (Theo Wargo/Getty Images)