Humans have lived in what is now Myanmar for at least 15,000 years. Bronze Age artifacts have been discovered at Nyaunggan, and the Samon Valley was settled by rice agriculturalists as early as 500 B.C.
In the 1st century B.C., the Pyu people moved into northern Burma and established 18 city-states, including Sri Ksetra, Binnaka, and Halingyi. The principal city, Sri Ksetra, was the power-center of the region from 90 to 656 A.D. After the seventh century, it was replaced by a rival city, possibly Halingyi. This new capital was destroyed by the Nanzhao kingdom in the mid-800s, bringing the Pyu period to a close.
When the Khmer Empire based at Angkor extended its power, the Mon people from Thailand were forced west into Myanmar. They established kingdoms in southern Myanmar including Thaton and Pegu in the 6th to 8th centuries.
By 850, the Pyu people had been absorbed by another group, the Bamar, who ruled a powerful kingdom with its capital at Bagan. This began the first Myanmar empire which was established by a Burman ruler, King Anawrahtar, in 1044 AD. The Bagan Kingdom slowly developed in strength until it was able to defeat the Mon at Thaton in 1057, and unite all of Myanmar under one king for the first time in history. The Bagan ruled until 1289, when their capital was captured by the Mongols. After the fall of Bagan, Myanmar was divided into several rival states, including Ava and Bago.
A second kingdom was established in the 1527 and Myanmar unified once more under the Toungoo Dynasty, which ruled central Myanmar from 1486 to 1599. Toungoo over-reached, however, trying to conquer more territory than its revenues could sustain, and it soon lost its grip on several neighboring areas. The state collapsed entirely in 1752, partly at the instigation of French colonial officials.
A third kingdom was founded from 1752 - 1825. The period between 1759 and 1824 saw Myanmar at the apex of its power under the Konbaung Dynasty. From its new capital at Yangon (Rangoon), the Konbaung kingdom conquered Thailand, bits of southern China, as well as Manipur, Arakan, and Assam, India. This incursion into India brought unwelcome British attention, however.
The First Anglo-Burmese War (1824-1826) saw Britain and Siam band together to defeat Myanmar. However, the British soon initiated the Second Anglo-Burmese War in 1852. Finally in 1886 the British gained control of Burma, and added the rest of the country to its Indian sphere after the Third Anglo-Burmese War. Burma was administered as a province of India until 1937.
Although Burma produced a lot of wealth under British colonial rule, almost all of the benefit went to British officials and their imported Indian underlings. The Burmese people got little benefit. This resulted in the growth of banditry, protests, and rebellion.
The British responded to Burmese discontent with a heavy-handed style later echoed by indigenous military dictators. In 1938, British police wielding batons killed a Rangoon University student during a protest. Soldiers also fired into a monk-led protest in Mandalay, killing 17 people.
During World War II (1942-45) Burmese nationalists allied themselves with Japan. The Japanese invaded and occupied the country. In 1945, Britain, with the assistance of the Anti-Fascist People’s Freedom League (AFPFL) led by Aung San, U Nu and others, liberated Burma from Japanese occupation. An interim government was set up until independence was gained through a new constitution in 1948.
When Aung San left the army in 1945, he became the recognised leader of the AFPFL. In 1946 Aung San was elected prime minister of Burma but was assassinated in 1947 before taking office. The loss of any recognised leader led to political instability. The Panglong Agreement of 1947 with the Sha, Kachin and Chin tribes created a unified Burma.
In 1948 Burma became independent from British rule with U Nu as the first prime minister, and a new constitution was established based on a democratically elected parliament. However, the government was almost immediately challenged by communist and ethnic groups and periods of intense civil war resulted. Although the constitution had declared some level of independence for the minority states, in fact they were never given this autonomy.
In 1958, the military, under the direction of General Ne Win, removed Prime Minister U Nu from office in order to restore political order. Although Ne Win allowed U Nu to be re-elected as prime minister in 1960, two years later, in 1962, he led a coup abolishing the constitution and establishing a military government with socialist economic priorities (Burma Socialist Programme Party).