The revolution of 1950-51 resulted in the overthrow of the Rana system (see The Growth of Political Parties The Return of the King , ch. 1). In 1951 King Tribhuvan Bir Bikram Shah announced by royal proclamation an interim government and an interim constitution until a new Constituent Assembly could be elected. The interim constitution, based on principles in India's constitution and entitled the Interim Government of Nepal Act, 1951, ratified the end of the authority of the prime minister and the system surrounding that office. It also reasserted the king's supreme executive, legislative, and judicial powers. The king exercised his executive authority through, and was aided and advised by, a Council of Ministers, which he appointed and which served at his pleasure.

The king also appointed an Advising Assembly to sit until the Constituent Assembly was elected. The king retained sovereign and plenary legislative powers. The Advising Assembly was, with certain exceptions, authorized only to discuss matters and to recommend measures to the king for enactment into law. The final authority to approve any legislative measure lay with the king. The constitution also established a Supreme Court, made the king supreme commander of the armed forces, reiterated and enlarged upon the fundamental rights included in the Rana constitution, and proclaimed numerous social and economic objectives of the government. These objectives were to promote the welfare of the people by securing a social order in which social, economic, and political justice pervaded all the institutions of national life. King Mahendra (reigned 1955-72) vigorously sought to broaden the monarch's political base, but the Nepali National Congress succeeded in gaining some democratic reforms. Although the constitution was expected to be temporary pending the election of a Constituent Assembly and the preparation of a permanent organic law, King Mahendra was unable to resist the increasingly well-orchestrated political demands by the Nepali National Congress for a more democratic and representative government, and was forced to promulgate a new constitution.

Data as of September 1991