The nineteenth-century Russian poet Fedor Tiutchev rightly marvelled at his motherland’s remarkable growth: ‘Moscow, and Peter’s town, and Constantine’s city, these are the Russian realm’s cherished capitals … But where is its limit? Where are its borders? The fates will reveal them in times to come …’ Over the past 400 years an obscure principality deep in the forests on Europe’s eastern edge had expanded to become the largest continental empire on Earth – a domain whose immense territory stretched from the Baltic Sea to the Pacific Ocean and beyond, covering one-sixth of the planet’s dry surface. Although somewhat diminished in size after the collapse of the Soviet Union in 1991, Russians today still nickname their country ‘the seventh continent’.