What did Vladimir Lenin identify as the three main stages of modern imperialism?

Three periods in the modern era witnessed the creation of vast empires, primarily colonial. Between the 15th century and the middle of the 18th, England, France, the Netherlands, Portugal, and Spain built empires in the Americas, India, and the East Indies. For almost a century thereafter, relative calm in empire building reigned as the result of a strong reaction against Imperialism. Then the decades between the middle of the 19th century and World War I were again characterized by intense imperialistic policies.