Nothing beats being young and rich. While most people attain multi-million dollar and billion dollar fortunes in their 40s and 50s, a few savvy entrepreneurs hit the big time while in their 20s and 30s.

Mfonobong Nsehe, who contributes for Forbes reported that there are a handful of young African entrepreneurs who’ve legitimately built multi-million dollar companies while in their 20s and 30s.

A few of them have taken the helm of small companies and spun them into companies with valuations of $1 billion or more.

All aged 39 and under, they are worth watching closely.

Mohammed Dewji, Tanzania: Manufacturing
Dewji, 38, a Tanzanian businessman and politician, is the CEO and leading shareholder of Mohammed Enterprise Limited (METL), one of the largest industrial conglomerates in East Africa. 
His father, Gulam Dewji, founded the conglomerate decades ago as a trading company but ‘Mo’ as he is popularly called, now calls the shots. 
He was solely responsible for engineering the group’s transformation from a trading house to a manufacturing powerhouse. 
METL, which records an annual turnover of close to $2 billion, owns 21st Century Textiles, one of the largest textile mills in sub-Saharan Africa by volume.
The group also manufactures soap, beverages, edible oils and other food products as well as bicycles and motorcycles.
Other assets include an insurance firm, a petroleum marketing outfit and a container depot in Tanzania’s capital city of Dar Es Salaam. 
The group employs over 24,000 full-time employees. Mo  Dewji is a World Economic Forum Young Global Leader and a Member of Parliament for Tanzania’s Singida Urban constituency.
 (I met with Dewji in Tanzania recently and will be writing a detailed piece on Dewji’s business holdings).

Igho Sanomi, Nigeria: Oil Trading
In 2004, Igho Sanomi founded the Taleveras Group, a Nigerian energy trading company. Taleveras trades over 100 million barrels of crude oil as well as several million tons of gasoline, LPG and jet fuel.
In April 2012, Taleveras acquired production sharing contracts (PSCs) for three offshore oil blocks in Ivory Coast.
In June 2013, Taleveras sold a 65% stake in one of its Ivorian offshore upstream projects to Lukoil of Russia for an undisclosed price. Taleveras also owns a stake in a power distribution firm in Nigeria. Sanomi is 38 years old.

Quinton van der Burgh, South Africa: Mining
The 36 year-old South African coal magnate is the founder and chairman of Quinton van der Burgh Investments, a diversified holding company that is the controlling shareholder in Eyethu Coal, a company that mines coal in South Africa’s Mpumalanga region. Eyethu owns two operational mines and is a major supplier of coal to Eskom, South Africa’s dominant power provider.
Van der Burgh’s portfolio also includes Iyanga Coal- a company that owns a mine with proven reserves of 18 million tons of coal and Burgh Plant Hire- a company that leases earth-moving equipment to clients like BHP Billiton, Xstrata and Anglo-American.
Van der Burgh is also a TV personality. He stars in Clifton Shores, an American/South African reality show filmed in Cape Town.

Gerald Wamalwa, Kenya: Engineering & Construction
In 2003, at age 28, Gerald Wamalwa quit his job as a field civil engineer and went on to start Mellech, an engineering outfit.
Today, Mellech Engineering & Construction is now one of East Africa’s leading construction and infrastructure engineering company.
The company offers services in the construction of building projects, roads, and water & sewer projects and related civil engineering infrastructure projects in Kenya, Southern Sudan and Uganda and grosses over $11 million a year revenues.
Wamalwa also owns ACP Telecoms, a company that provides turnkey telecommunication network infrastructure solutions.

Sibongile Sambo, South Africa: Private Aviation
Sibongile Sambo, 39, is the founder of SRS Aviation, a successful South African private aviation company. SRS started off in 2004 by brokering contracts between aviation services and those with air-transport needs. Later in the year, when the South African government invited aviation service companies to bid on a lucrative contract for cargo transport, SRS won the bid. Over time, SRS morphed from its cargo business into an integrated provider of private aviation services. SRS now offers clients from Southern Africa professional and personal flight options to international destinations including VIP Charter, tourist charter and helicopter services. The company also provides maintenance, sales and fleet management services to private jet owners. SRS refused to disclose revenues, but a source in the company says annual revenues are several million dollars.

Khanyi Dhlomo, South Africa: Publishing
The Harvard MBA grad and South African media mogul began her career as a news presenter at SABC, the television station owned by the South African government, at age 20 while she was still a journalism student at the University of Witwatersrand.
She went on to become the editor of True Love, a popular South African women’s magazine at age 22. In 2007, she founded Ndalo Media, a 50-50 joint venture with Media 24, the publishing arm of Naspers, Africa’s largest media company.
Ndalo Media publishes Destiny and Destiny Man, two of South Africa’s most popular lifestyle magazines. Ndalo also publishes Sawubona, the in-flight publication for South African Airways, which is distributed on all local and international SAA flights.
 She also owns Luminance, a startup high-end fashion and lifestyle store in South Africa.

Patrick Ngowi, Tanzania: Alternative Energy
Ngowi, a 28 year-old Tanzanian, is the founder of Helvetic Solar, East Africa’s leading renewable energy company. Companies in the group are involved in the handling, supply, installation and maintenance of hydro turbines, solar power and thermal systems in East Africa.
According to Ngowi, Helvetic’s revenues are expected to hit $7 million before the end of this year and the company is extremely profitable.
 The company’s major clients include the United Nations, World Vision and the Tanzanian Army. An emerging philanthropist, he offers basic lighting facilities to Tanzania’s rural poor through his Light For Life foundation.

Ken Njoroge, Kenya: Mobile technology
Njoroge, 37, is the founder of Cellulant, a leading Pan-African mobile commerce company that manages, delivers and bills for content and commerce services over mobile networks.
Cellulant provides mobile banking, mobile payments, music, information services and other mobile related services. 
Njoroge founded the company in 2004 along with a Nigerian partner, Goke Akinboro. It now has a presence in 8 African countries and boasts a clientele of African blue-chips like Barclays Bank, Standard Chartered, MTN and other companies. Cellulant’s revenues for 2012 exceeded $120 million.

Colin Thornton, South Africa: Computer Services
In 1998, when he was 20, South African computer whiz Colin Thornton dropped out of the University of Witwatersrand where he was pursuing a BSc in Computer science.
He raised $1,000 (R5, 000) from friends and family to print out flyers and other marketing material promoting his startup company which would fix computers.
Today, that company is Dial-A-Nerd, a company that provides computer support services dedicated to homes and businesses.
Dial a Nerd’s team of mobile technicians are able to repair, build, upgrade or even replace PCs at your premises. The company has annual revenues of close to $10 million, 14 branches and 150 staff.

Alan Knott-Craig Jr., South Africa: Technology, Investments

The 36 year-old South African entrepreneur is the founder of World Of Avatar (WOA), the private investment holding company that acquired MXit from Namibian founder Herman Heunis and Naspers for $50 million in August 2011.
Mxit is a mobile instant messaging services which offers social networking, mobile voice clips, music & entertainment, banking access and other community-based applications.
It currently has over 20 million users. Alan also has stakes in popular South African online publication Daily Maverick; advertising network Shinka, which sells ad space on MXit; and market research company Pondering Panda. Alan is a 2009 World Economic Forum Young Global Leader.