Mandaric took control of his father’s engineering business in the Serbian city of Novi Sad at the age of 21.
Five years later it was one of the largest firms in Yugoslavia and on a collision course with Marshal Tito, country’s communist dictator.
Tito denounced Mandaric as a “capitalist traitor” when the entrepreneur took his family to Switzerland.
Mandaric spent a year there, desperately trying to get his cash out of the Balkans, then moved to United States where he founded a computer-components firm and an electronics business.
He acquired US citizenship and signed George Best to play for the first professional sports team in Silicon Valley, the San Jose Earthquakes.
Frustrated by the slow progress of the game in the US, Mandaric bought Belgian club Charleroi and then moved on to Nice.
Portsmouth were on the brink of bankruptcy when he bought them in 1999 before being revived under his stewardship in a pattern which would earn him a reputation as football’s ‘Mr Fixit’.
There would be the wobbly start as owner and club got acquainted, a few spins of the managerial merry-go-round, investment in the squad, improvement, promotion, consolidation, sale.
With Harry Redknapp appointed as manager, Mandaric’s Portsmouth won the Championship in 2003 before he sold the club to French-Israeli businessman Alexandre Gaydamak for £32m in 2006.
Mandaric bought Leicester City for £6m in 2007. The Foxes were relegated to League One in 2007-08 but returned as champions in 08-09 and lost in the Championship play-off semi-finals in 09-10.
He sold Leicester to Thailand’s Vichai Srivaddhanaprabha for £40m later that year and bought a heavily indebted Sheffield Wednesday for £1.
The Owls won promotion from League One in 2012 before Mandaric sold them to another Thai, Dejphon Chansiri, for £37.5m.
Manadaric was also memorably involved with Redknapp in a corruption saga that started with a BBC Panorama investigation in 2006, and ended with them being acquitted of tax evasion in 2012.
Earlier this year, Mandaric considered buying back Wednesday to save the club from being “destroyed” under current chairman Chansiri.
However, he decided against pursuing the idea because he could not devote sufficient time to “return the club to the healthy condition I left it in”.