Economic expansion was accelerated in the early years of the 20th century by the acquisition of the vast territory of the Congo, now the Republic of Zaire. Belgian industry was severely damaged by World War I and suffered major setbacks during the depression of the 1930s. However, postwar reconstruction and adaptation to the technological revolution, along with the formation of wider international economic areas, quickly improved Belgian industry. New industries, including petrochemicals, have come into existence in Belgium and have steadily expanded. The governing document is the Constitution, which lays down the prerogatives and defines the separation of powers.
Judicial power is the province of the courts.
Legislative power is exercised by Parliament, and executive power is exercised by the King and his ministers. Parliament consists of two assemblies, the Chamber of Representatives and the Senate. The Chamber of Representatives and the Senate currently have the same powers to propose legislation and to vote upon it. The government consists of the King and his ministers, and its authority is founded on the support of a majority in Parliament. Belgium was a centralized unitarian state with national laws and national Parliament, governed by a national government until 1970.