Charles Cadogan's fortune has risen alongside increasing property values in London. He and his family own an extensive real estate portfolio worth more than $6 billion that dates back to the Georgian kings. They are best known for redeveloping Sloane Street, a popular shopping destination in London named after an ancestor, with a new plaza of high-end shops. Cadogan, who began his career at merchant banker Schroder Wagg, turned over everyday duties to his son Edward in 2012 but still pontificates on market conditions. He recently warned that London's hot real estate market may soon cool off. The Cadogan clan's 90-acre estate stretches across the capital's most desirable neighborhoods of Chelsea and Knightsbridge.