The Federal Constitution of Malaysia, which came into force in 1957, is the supreme law of Malaysia. The Federation was initially called the Federation of Malaya (in Malay, Persekutuan Tanah Melayu) and it adopted its present name, Malaysia, when the States of Sabah, Sarawak and Singapore (now independent) joined the Federation. The Constitution establishes the Federation as a constitutional monarchy having the Yang di-Pertuan Agong as the Head of State whose roles are largely ceremonial. It provides for the establishment and the organization of three main branches of the government: the bicameral legislative branch called the Parliament, which consists of the House of Representatives (in Malay, Dewan Rakyat) and the Senate (Dewan Negara); the executive branch led by the Prime Minister and his Cabinet Ministers; and the judicial branch headed by the Federal Court.
The document also defines the rights and responsibilities of the federal government, the member states of the federation and the citizens and their relations to each other.