A country of South Asia. Occupying land crisscrossed by ancient invasion paths, Pakistan was the home of the prehistoric Indus Valley civilization, which flourished until overrun by Aryans c. 1500 BC. After being conquered by numerous rulers and powers, it passed to the British as part of India and became a separate Muslim state in 1947. The country originally included the Bengalese territory of East Pakistan, which achieved its separate independence in 1971 as Bangladesh. Pakistan became a republic in 1956. Islamabad is the capital and Karachi the largest city.