E-Sir was born Issah Mmari, on May 20th 1981 in California, Nairobi, Kenya. He went through Primary School at St Ann's Junior Academy and later attended High School at Brook-House Senior School. It was during high school that E-Sir started rhyming and writing poetry initially for fun.

In 1998 E-Sir decided to take his music seriously and achieve his lifelong dream, of owning a recording studio. For two years he shopped around for the right producer without much success. Among the challenges that E-Sir had to face included ‘fake’ managers, ‘fake’ producers, ‘fake’ promoters and wanna -be MCs. He even recorded some songs, but was not happy with the final product.

Eventually in late 1999 he met DJ Luke of the Production House Ogopa DeeJay’s.

After the first recording E-Sir developed a working relationship with Ogopa and as he once said, "Ogopa has made a very big impact on the music industry. This is because they respect the Artistes’ wishes, at the same time directing the Artiste into giving Kenyans what they want”.

His debut single ‘Jo’ featuring long time friend Big Pin got the industry talking about the ‘new kid on the block’. The song received massive positive response and E-Sir broke into mainstream radio.

After the success of the much acclaimed album ‘Ogopa 1 - Kenya Club Classics’, Ogopa Deejay’s released ‘Ogopa 2 - Strictly For The Hanye In You’ in 2002 and ‘Leo ni Leo’,- another E-Sir classic, featured prominently. This song also featured prominently on the Kenya Radio play list. E-Sir proved he was no one ‘Hit’ wonder, the new kid on the block was a force to respect.

Towards the end of the year E-Sir released his much awaited debut album titled ‘Nimefika’, which went on to become one of  the most popular  urban contemporary albums in East Africa. Virtually all the released singles from the album have topped East African charts.

Sadly, E-Sir passed away on Sunday, March 16th 2003, in a Tragic Road Accident, on his way home after a performance in Nakuru, a town in the Rift Valley in Kenya, he was buried in the Muslim cemetery in Nairobi in a funeral attended by hundreds of his fans, celebrities and people of all walks of life.

The album ‘Nimefika’ was by far the most successful album by a local artiste in recent years. The music the lyrics and the style of the album was such that It reached out to people of all ages and touched every one in a special way. A manifestation of this is clearly expressed at the number of awards it scooped received at the Chaguo la Teeniez Awards on April 17th 2003 and the Kisima Awards on June 21st 2003 where E-Sir also scooped the highest number of awards posthumously.

In character, his humility touched many fans, especially the teenagers and small children who always lined up for his autograph after a performance, an appearance or even when he was up and about in his neighborhood.

Finally it is important to note that E-Sir believed in himself, his music and his abilities as a performing artiste. And to illustrate this in his own words he once said "Industry peeps are all up in my business claiming that I am changing the game. If that is so I think Kenyans have long been awaiting the change. I love my hood, my friends, my family and my fans. I love my life, live it or leave it; the choice is yours”. May God Almighty Rest His ‘Soul’ in Eternal Peace.