Although there is evidence of people being in Burma for more than 13,000 years, the first recorded inhabitants were the Pyu, who originated in southern China and arrived in about 200 B.C.E. They established city states and trade routes to India and China, which caused the Pyu to be introduced to Buddhism, now Burma's primary religion. The Chinese described them as a peaceful people who wore cotton rather than silk so they did not harm the silkworms. Different groups began to attack Burma until the whole area was united under Anawratha Minsaw's Pagan Empire in 1044. Minsaw is known today as the father of Burma, he layed the foundation for the countries religion and culture. The Pagan Empire would remain the dominant government until 1277, when the mongols reached Burma.
The area was soon taken over the Myinsaing, a neighboring kingdom that had managed to hold off the Mongols. However, this was short lived, and soon the kingdom split into four, with constant war until 1599, when the nation was reunified under the Restored Taungoo Kingdom. There was relative peace for the remainder of the 17th century. Rulers and warmongers came and went until the Anglo-Burmese wars, which went on and of from 1824 to 1886. They ended in the complete annexation of the Burmese kingdom by the British empire, and its integration into the colony of the British Raj (India).
Not much occurred of interest until the second world war. The Japanese, who were at war with the British Empire, attacked Burma in an attempt to attack India. After years of jungle warfare, the Japanese were pushed out of Burma. Around 200,000 Burmese died under Japanese occupation.
After the war, Aung San, who helped unite the Burmese people to fight the Japanese, signed an agreement with the British for Burmese independence. Unfortunately he and his cabinet were assassinated by the conservative wartime prime minister U Saw. Burmese independence came to fruition in 1948.
From 1948 to 1962, Burma saw an improved economy and foreign aid. However, this time was also a time of political unrest, as socialist ideal seeped in from Communist China, who had won a civil war against the nationalists, led by Chan Kai Shek, in 1949. In 1962, Ne Win staged a coup d'etat of his own, turning Burma into a socialist state with a closed economy and one party system. Peaceful protests were crushed by the military, including a student protest that left 100 dead.
After Ne Win retired in 1988, the economy began to improve with more foreign aid, but "falling commodity prices and rising national debt eventually lead to demonetisation of particular bank notes which wiped out the savings of most of the people of Burma." (Source: https://www.rickshawtravel.co.uk/blog/a-brief-history-of-burma-why-it-became-myanmar/) This led to riots and the military declaring martial law. This led to the 8888 uprising (the date was 8/8/88), with pro-democratic demonstrators led by the daughter of Aung San, Aung San Suu Kyi. In 1989 the military officially ended the socialist state and changed the country's name to Myanmar. In a 1990 election the National League for Democracy (NLD) Defeated the National Unity Party (The successor to the military regime) with 90% of the popular vote, which made Aung San Suu Kyi the president. However, the military intervened and held her in house arrest until 1995, then again from 2000 to 2002. In 1991, Kyi won the Nobel Peace Prize. Reforms in 2011 released political prisoners and brought back free elections in 2012, in which Kyi's democratic party won 41 out of 44 parliamentary seats. In 2016, Aung San became the State Counselor, a position similar to Prime Minister.
Source: https://www.rickshawtravel.co.uk/blog/a-brief-history-of-burma-why-it-became-myanmar/