Once viewed as a possible successor to her father Jose Eduardo dos Santos, her investments in Angola and former colonial ruler Portugal are worth about $3 billion (2.5 billion euros), according to Forbes magazine.
But the decision of her father’s successor President Joao Lourenco to remove her as chief executive of state oil company Sonangol marks a dramatic reversal for the woman known by her detractors as “the princess”.
Her abrupt removal will come as a shock to Angola’s ruling elite, as she had repeatedly stated that she wanted to remain in the top job.
“The job of Sonangol chief executive is not dependent on the electoral process… I want to continue,” she said ahead of the August elections.
Aged 44 and married with three children, she emerged as a serious presidential succession candidate in June 2016 after her appointment to head the state oil firm which generates much of Angola’s wealth.
Critics say she has amassed her vast fortune thanks to the backing of her authoritarian father who ruled the country with an iron grip for nearly 40 years.
However she puts her personal success down to driving ambition, saying she has always kept a clear divide between her business career and her father’s position.
“I’m not financed by any state money or any public funds. I don’t do that,” she said in an interview with the Wall Street Journal in 2016.
“I’m tremendously independent, I always had this wish to stand alone and not be in my parents’ shadow.”
Among her key assets are a 25-percent stake in Unitel, Angola’s largest phone operator, seven percent of Portugese oil and gas giant Galp Energia, and major bank stakes in both countries.
She also has a controlling share of a Portuguese cable TV and telecom firm.
– ‘Ordinary childhood’? –
She was born in Baku, Azerbaijan in 1973 where her father was studying, but her family returned to Angola soon afterwards.
She said she had an ordinary childhood, walking to school — and selling chicken eggs for profit — even after he became president in 1979 as the country descended into a long and bloody civil war.
When her parents separated, she moved with her mother to London, attending an elite private school and then taking a mechanical and electrical engineering degree at King’s College.
She says she lived in basic student accommodation in London, and worked so hard that she had little time to party, especially with parents that she remembers being “very demanding”.
Today she is married to art collector and businessman Sindika Dokolo who is from the Democratic Republic of Congo, and moves regularly between Luanda, Lisbon and London.
She is proud to claim she drives around the choked streets of Luanda and works seven days a week.
She gives few interviews and makes only occasional appearances in public, once being photographed with her father and US singer Mariah Carey at a concert in the Angolan capital Luanda.
The concert in 2013 — sponsored by Isabel’s firm Unitel — sparked fury as Carey was reportedly paid a $1 million for singing in a country with a grim human rights record, widespread corruption and abject poverty.
As news of her extraordinary wealth has spread, such criticism has sharpened, including four EU parliamentarians who in 2015 called for an investigation into her Portuguese interests and alleged funding from her father.