Isabel Dos Santos, the eldest daughter of the president of Angola, Jose Eduardo Dos Santos, has been anointed as Africa's first woman billionaire, according to a new survey by Forbes magazine in the U.S.

Isabel, only 40, passed the $1 billion threshold after acquiring shares in a number of Portuguese-based public companies, including cable television provider Zon Multimedia Servicos de Telecomunicacoes e Multimedia SGPS (Lisbon: ZON), and bank Banco BPI (OTC: BBSPY).

She already owned stakes in at least one Angolan bank, Banco BIC.

With a total 28.8 percent holding in Zon -- valued at some $385 million -- she is the corporation’s largest individual stakeholder. Her 19.5 percent stake in BPI is valued at a cool $465 million.

Moreover, her 25 percent share in Banco BIC is worth at least $160 million.

In addition, Isabel also sits on the boards of several companies in both Portugal and Angola, including telecom giant Unitel.

Forbes noted that Isabel studied mechanical and electrical engineering in London, before opening a restaurant in the Angolan capital of Luanda in 1997, when she was 24.

Agence France Presse noted that Isabel speaks many languages and is married to Sindika Dokolo, a Congolese art collector.

Isabel’s mother, Tatiana Kukanova, is from Azerbaijan -- her parents are separated.

Regarding Isabel’s dramatic acquisition of massive wealth in such a short period of time, Peter Lewis, professor of African Studies at Johns Hopkins University’s School for Advanced International Studies, told Forbes: “It’s clear through documented work that the ruling party [of Angola] and the President’s inner circle have a lot of business interests. The source of funds and corporate governance are very murky. The central problem in Angola is the complete lack of transparency. We can’t trace the provenance of these funds.”

Indeed, Isabel’s father has ruled Angola – which is at peace now for more than a decade following 27 years of a devastating civil war -- since 1979.

Jose Eduardo Dos Santos is Africa's second-longest-ruling leader after Equatorial Guinea's Teodoro Obiang Nguema.

BBC commented that Jose Eduardo, who was never formally elected president, has a tight grip on Angola’s armed forces, media and judiciary, but keeps a very low profile.

“When you tease out the ownership and controlling interests in Angola it reads like a ‘Who’s Who’ of [the President’s] family members and party and military chiefs,” Lewis added.

Meanwhile, Angola is flush with foreign cash that has poured into its various industries, especially the lucrative petroleum sector.

“They are fixing a few roads and there are some railways and there are a lot of cranes in Luanda,” Lewis noted.

“But they are awash in cash; $5 billion has been documented in illicit financial flows.”

Despite Angola’s oil wealth, it remains one of the poorest nations on earth. According to the CIA/World Factbook, more than 40 percent of the population lives in poverty. Most of the country’s citizens live on $2 a day.

Forbes' mention of Isabel was part of a larger collection of Africa’s 40 wealthiest individuals -- who have an aggregate worth of some $72.9 billion, up 12 percent over the prior year. Isabel is one of only two women on the super-rich list.

The other woman is Folorunsho Alakija of Nigeria, who owns a significant stake in Agbami oil field and has significant interests in fashion and print.

The wealthiest African for the second year in a row is Nigerian cement mogul Aliko Dangote, blessed with a net worth of $12 billion, up from $10.1 billion in November 2011.

Coming in second place, Nicky Oppenheimer, scion of South Africa’s fabulous De Beers diamond fortune, valued at $6.4 billion (although down $100 million from the past year).