The document summarizes the key features of the constitutions of Pakistan from 1956 to 1973. The 1956 constitution established Pakistan as an Islamic republic with Urdu and Bengali as national languages. It had a unicameral legislature and parliamentary system of government. The 1962 constitution made it more difficult to amend and gave the president significant powers. The 1973 constitution is the current governing document which is a rigid, written constitution with a parliamentary democracy and bicameral legislature. It declares Islam as the state religion and protects fundamental rights and minorities.