Alexander Otto: $8.8 billion (£6.8bn)
Much of Alexander Otto’s wealth stems from his share of the Otto Group, a mail order firm his father Werner built in postwar Germany.
The family built up an empire of more than 40 firms in the worlds of retail, finance and property. Alexander has been CEO of their real estate firm ECE since 2000, managing around 200 shopping centres across Europe. He is married to wife Dorit (pictured) but they don't have any children.