Justin Bieber

Justin Bieber celebrated his four-year anniversary at the top of the pop charts on Sunday. The pop star became famous in 2009 when his covers went viral on YouTube channel and he debuted his first album “My World” that year.

Bieber thanked fans for their support and love on Twitter through the years.

"4 years ago i released #MyWorld and now we are here today. So much has happened for us and im grateful. Thank you Beliebers. I love you," he wrote.

The 19-year-old singer is on a world tour promoting his third album “Believe”. He will play in Mexico City on Monday, followed by tours of New Zealand, Australia and Europe.