A Conservative Member of Parliament (1837), he became governor-general of India (1848–56), when he oversaw the extension of British rule through the annexation of the Punjab (1849), of Lower Burma (1852), of Oudh (1856), and of several smaller Indian states, through the use of the so-called Doctrine of Lapse. According to this Britain annexed those states where there was no heir who was recognized by Britain. Dalhousie initiated major developments in communications, including the railway (1853), the telegraph and postal system, the opening of the Ganges canal, and in public works and industry. He removed internal trade barriers, promoted social reform through legislation against female infanticide and the suppression of human sacrifice, and fostered the development of a popular educational system in India. He introduced improved training of the Indian civil service, which was opened to all British subjects of any race.