Eaton Square in Belgravia, London, where  aluminium magnate Oleg Deripaska has a residence: he appeared on a list of Russian oligarchs published by the US Treasury last January in connection with new sanctions legislation. Photograph:Tolga Akmen/AFP/Getty

Tucked behind Kensington Palace and protected by armed police at checkpoints on either end is the street known as Billionaire’s Row, the most expensiv(...)