The expansion phase, 1500 to 1900
European overseas empires grew in two main waves. The first, led by Spain and Portugal after 1492, claimed the Americas and trade routes around Africa and Asia. The Treaty of Tordesillas split the non-European world between them in 1494. A later wave brought Britain, France, and the Netherlands to dominance, culminating in the Scramble for Africa, where the 1884 to 1885 Berlin Conference partitioned nearly the entire continent among European powers within a few decades.
Rapid decolonization after 1945
Most colonial empires unwound within a single generation after the Second World War. India and Pakistan gained independence in 1947, a wave of African states followed around 1960 (often called the Year of Africa, when 17 became independent), and the process largely concluded by 1980 with Zimbabwe. The reversal was driven by exhausted European treasuries, rising nationalist movements, and a postwar international order increasingly hostile to formal empire.