Muhammad Zahir Shah inherited the throne of Afghanistan
in 1933 at the age of nineteen, although he was not deemed old enough to rule until 1953.
During a dispute with Pakistan which lead to border closings and, therefore, cessation of trade with India, Zahir Shah dissolved the Afghani government. He appointed entirely new ministers (none of whom were of the royal family), and proclaimed a new constitution in 1964. Afghanistan's new government retained the King as head of state, but consisted of independent executive, legislative, and judicial branches. Members of the royal family were prohibited from holding high office. Afghanis were now also allowed freedom of the press and the right to form political parties.
The consitutional government suffered from its members' general inexperience with democracy. Most legislators had, until recently, been essentially feudal or religious potentates. Zahir Shah had to occasionally resort to Royal Decree to get anything done. Despite this, there was a welcome general elevation of the standard of living across Afghanistan.
Zahir Shah's reign came to an abrupt end in 1973; he was overthrown in a bloodless coup while on a trip to Europe. Daoud Khan, the overthrower, proclaimed a Republic and assumed the roles of president and prime minister.