On 4 January 1948, Myanmar gained independence from the United Kingdom. The communists and the ethnic minorities in the country were dissatisfied with the newly formed government, believing that they were being unfairly excluded from governing the country.
On 2 April 1948, the CPB (the Communist Party of Burma) fired the first shots of the conflict in Paukkongyi, Pegu Region (present-day Bago Region).
The Karen people of Kayin State (formerly Karen State) in eastern Myanmar are the third largest ethnic group in Myanmar, consisting of roughly 7% of the country's total population. Karen insurgent groups have fought for independence and self-determination since 1949.
In 1949, the commander-in-chief of the Tatmadaw General Smith Dun, an ethnic Karen, was fired because of the rise of Karen opposition groups, which furthered ethnic tensions. He was replaced by Ne Win, a Bamar nationalist who would go on to become the dictator of Myanmar.
During the Tatmadaw's (Myanmar Armed Forces') heavy militarisation of the state in the late 1940s and early 1950s, locals accused them of mistreating, torturing, robbing, raping, unlawfully arresting and massacring villagers. As a result, on 21 May 1958, an armed resistance movement, led by Sao Noi and Saw Yanna, was started in Shan State.
After three successive parliamentary governments governed Myanmar (Burma), the Tatmadaw (Myanmar Armed Forces), led by General Ne Win, enacted a coup d'état in 1962, which ousted the parliamentary government and replaced it with a military junta.
In 1967, following China's initiation of the Cultural Revolution, violence broke out between local Bamars and overseas Chinese in Myanmar, leading to anti-Chinese riots in Rangoon (present-day Yangon) and other cities.
The initial aim of the largest Karen opposition group, the Karen National Union (KNU), and its armed wing, the Karen National Liberation Army (KNLA), was to obtain independence for the Karen people. However, since 1976 they have instead called for a federal union with fair Karen representation and the self-determination of the Karen people.
On 8 August 1988, students began demonstrating in Rangoon (Yangon) against General Ne Win's rule and the disastrous Burmese Way to Socialism system.
The Myanmar National Democratic Alliance Army (MNDAA) is a Kokang insurgent group active in the Kokang Self-Administered Zone in northern Shan State. The group signed a ceasefire agreement with the government in 1989, the same year it was founded, which lasted for two decades until 2009, when violence erupted between the group and government forces.
Most notably a ceasefire signed in 1994, that lasted for 17 years until June 2011, when government forces attacked KIA positions along the Taping River, east of Bhamo, Kachin State.
In 2006, the Tatmadaw (Myanmar Armed Forces) conducted a large military offensive against the Karen National Union (KNU) in Kayin State, which resulted in the displacement of hundreds of thousands of civilians. One estimate claimed that approximately half a million people were displaced due to fighting between government forces and the KNU, and the forcible relocation of villages by the government.
In 2007, hundreds of thousands of monks protested against the military junta's rule, and called for free elections, minority rights and the release of political prisoners in an event now known as the Saffron Revolution.
Ethnic Rakhine insurgent groups, such as the Arakan Army and Arakan Liberation Army (ALA), continue to have hostilities towards the government, though major violence has been rare since political reforms and peace talks. The Arakan Army, founded in 2009, is currently the largest insurgent group in Rakhine State, with 1,500–2,500 fighters active in the region.
In 2011, the government introduced a new constitution following political reforms, and thousands of political prisoners were released, including Aung San Suu Kyi.
In 2011, Tatmadaw (Myanmar Armed Forces) launched a military offensive named Operation Perseverance against insurgents in Shan State in 2011. During the offensive, the Tatmadaw captured territory from the National Democratic Alliance Army (NDAA) and the Shan State Army - North (SSA-N), with the latter being involved in most of the fighting.
The SSA-S (the Shan State Army - South) maintains bases along the Myanmar–Thailand border, and signed a ceasefire agreement with the government on 2 December 2011.
In 2012 alone, fighting between the KIA and the government resulted in around 2,500 casualties (both civilian and military); 211 of whom were government soldiers.
One of the largest Shan insurgent groups in Myanmar is the Shan State Army - South (SSA-S), which has around 6,000 to 8,000 soldiers, and was led by Yawd Serk until his resignation on 2 February 2014.
Government forces attacked the Kachin Independence Army's headquarters near the city of Laiza on 19 November 2014, killing at least 22 KIA insurgents, according to the government.
Between February and May 2015, government forces launched a series of military operations in Kokang, in northern Shan State, after the Myanmar National Democratic Alliance Army (MNDAA) attempted to retake territory it had lost in 2009.
The Nationwide Ceasefire Agreement (NCA) was a landmark agreement signed between the government of Myanmar and eight insurgent groups on 15 October 2015; two other insurgent groups later joined on 13 February 2018.
The Union Peace Conference - 21st Century Panglong was held from 31 August to 4 September 2016 with several different organisations as representatives, in an attempt to mediate between the government and different insurgent groups.
Insurgents of the Arakan Rohingya Salvation Army (ARSA) attacked Burmese border posts along the Bangladesh–Myanmar border on 9 October 2016, killing nine border officers.
On 9 October 2016, unidentified insurgents attacked three Burmese border posts along Myanmar's border with Bangladesh, starting a new armed conflict in northern Rakhine State.
According to government officials in the border town of Maungdaw, the attackers looted several dozen firearms and ammunition from the border posts, and brandished knives and homemade slingshots that fired metal bolts. The attacks left nine border officers and "several insurgents" dead.
11 October 2016, four Tatmadaw soldiers were killed on the third day of fighting. A newly emerged insurgent group, the Arakan Rohingya Salvation Army (ARSA), claimed responsibility a week later.
In late November 2016, the Northern Alliance which consists of four insurgent groups, the Arakan Army (AA), the Kachin Independence Army (KIA), the Myanmar National Democratic Alliance Army (MNDAA) and the Ta'ang National Liberation Army (TNLA), attacked towns and border posts along the China–Myanmar border in Muse Township, northern Shan State.
The insurgents (the Northern Alliance) captured the town of Mong Ko on 25 November 2016 and maintained control of it until they withdrew from the town on 4 December 2016 to avoid civilian casualties from airstrikes by the Myanmar Air Force.
On 25 August 2017, the ARSA (the Arakan Rohingya Salvation Army) launched a second large-scale attack against 24 police posts and the 552nd Light Infantry Battalion army base in northern Rakhine State. A total of 71 people were reportedly killed in the armed clashes.
During the early hours of 25 August 2017, ARSA (The Arakan Rohingya Salvation Army) insurgents launched coordinated attacks on 24 police posts and the 552nd Light Infantry Battalion army base, killing a dozen people.
However in March 2018, the government of Myanmar violated the agreement by sending 400 Tatmadaw soldiers into KNU-held territory to build a road connecting two military bases. Armed clashes erupted between the KNU and the Myanmar Army in the Ler Mu Plaw area of Hpapun District, resulting in the displacement of 2,000 people.
On 17 May 2018, the Tatmadaw agreed to "temporarily postpone" their road project and to withdraw troops from the area.
On 4 January 2019, around 300 Arakan Army insurgents launched pre-dawn attacks on four border police outposts—Kyaung Taung, Nga Myin Taw, Ka Htee La and Kone Myint—in northern Buthidaung Township.
Following the attacks, the Office of the President of Myanmar held a high-level meeting on national security in the capital Naypyidaw on 7 January 2019, and instructed the Defense Ministry to increase troop deployments in the areas that were attacked and to use aircraft if necessary.
On 15 August 2019, Northern Alliance insurgents attacked a military college in Nawnghkio Township, killing 15.
Further clashes occurred in the following days, with Myanmar's military warning there could be a full-scale war if the Northern Alliance did not halt their attacks.
The mission called for an investigation and the prosecution of military leaders, in particular commander-in-chief Senior General Min Aung Hlaing, in the International Criminal Court (ICC) for genocide, crimes against humanity, and war crimes.
On 11 November 2019, The Gambia filed a lawsuit in the International Court of Justice against Myanmar; State Counsellor Aung San Suu Kyi defended Myanmar's military generals against genocide accusations in public hearings in December 2019.
Myanmar has also taken an active role in finding and arresting insurgents that fled from northeast India; in May 2020 Myanmar handed over 22 insurgents, included several top commanders, to Indian authorities.
Similarly, India has been the only country to forcefully repatriate Rohingya refugees back to Myanmar despite a global outcry.