Various ethnic Burmese and ethnic minority city-states or kingdoms occupied the present borders through the 19th century, and several minority ethnic groups continue to maintain independent armies and control territory within the country today, in opposition to the central government. Over a period of 62 years (1824-1886), Britain conquered Burma and incorporated all the groups within the country into its Indian Empire. Burma was administered as a province of India until 1937 when it became a separate, self-governing colony; in 1948, following major battles on its territory during World War II, Burma attained independence from the British Commonwealth. Gen. NE WIN dominated the government from 1962 to 1988, first as military ruler, then as self-appointed president, and later as political kingpin. In response to widespread civil unrest, NE WIN resigned in 1988, but within months the military crushed student-led protests and took power. Since independence, successive Burmese governments have fought on-and-off conflicts with armed ethnic groups seeking autonomy in the country’s mountainous border regions.