When it comes to the world of hip-hop, there is only one king and his name is Dr. Dre! The American, rapper, producer, record label owner and entrepreneur recently eclipsed all competition when becoming No.1 on Forbes' 2014 Hip-Hop Cash Kings list.

Dr Dre
Dr. Dre earned an estimated $620 million last year

The 49 year-old music mogul earned this title by raking in a whopping $620 million in the past twelve months, which the magazine calculated from his "income from touring, record sales, publishing, merchandise sales, endorsements, and other ventures."

Dre's annual earnings mainly accumulate from this past May's transaction of Beats Music to Apple for a staggering $3 billion. As a result of this sale, he not only achieved "the highest yearly earnings total of any musician ever evaluated by Forbes," but also raked in more money than all the rappers' earnings combined on Forbes' list.

More: Everything We Know So Far About ‘Straight Outta Compton’ The N.W.A. Biopic

"It's safe to say headphones is a good business," DJ Kaled, who debuted on the list at No.20 with estimated earnings of $7 million, told Forbes.

Coming quite far behind Dre, in a tie for second place, were East Coast hip-hop icons P Diddy and Jay Z, who both brought in $60 million. Coming in fourth is Canadian rapper Drake with $33 million, and rounding off the top five is hip-hop's hottest new act, Macklemore & Ryan Lewis, earning $32 million.

More: Dr Dre & Jimmy Iovine Set Out To Conquer The Music Streaming Market With 'Beats Music'

Other notable names in the top 20 include Kanye West, Birdman, Lil Wayne, Pharrell Williams and Dr. Dre's close friend, Eminem.