The accurate description of Russia's evolving social geography is the decline of St. Petersburg and the rise of Moscow.
St. Petersburg served as the capital of the Russian Empire for over two centuries, from 1712 until 1918. It was the political, cultural, and intellectual heart of the nation. However, following the Russian Revolution, the Bolshevik government moved the capital back to Moscow in March 1918, citing security concerns during the Civil War.
Today, Moscow is a global megacity of over 13 million people, the primary engine of Russia's economy. St. Petersburg, with about 5.5 million residents, remains a vital cultural and tourist destination but no longer rivals Moscow in political or economic weight.