Born Issah Mmari, on May 20, 1981 in California Estate, and raised in South c estate Nairobi, Kenya, E-Sir was a Kenyan hip hop artist signed to the Ogopa DJs label who was famous for his deft lyrical ability and command of the Swahili language. He is still widely regarded as one the best rappers to emerge on the Kenyan hip hop scene. He first came to be known in 2001 by his song "Jo", a song done in the same style as Black Rob's "Whoa." The song proudly declared E-Sir's arrival on the Kenyan music scene and was featured on the Ogopa DJs debut album . He went on to release his debut album "Nimefika" in 2003 which was a big hit with virtually all the songs on the album becoming radio singles. He won 4 categories in the 2003 Kisima Music Awards.
E-Sir died in a road accident on March 16, 2003, while in the company of fellow label mate Nameless. He was on his way back from a concert in Nakuru town that was to help promote the album. His fans were shocked and grieved for days on end after hearing the news of his death. His death was considered coming at a time when his career was starting to take off. His other hits include "Moss Moss," "Boomba Train," "Hamunitishi" and "Leo ni Leo." His only posthumous song was the collaboration between him and Nameless called "Maisha".