In 2017 the Myanmar military launched a ferocious crackdown against its Rohingya Muslim population, leading about 740,000 to flee into neighbouring Bangladesh.
The 600,000 Rohingya remaining in the mainly Buddhist nation face a "serious risk of genocide", a UN fact-finding mission warned on Monday.
Here are key dates in the crisis since 2017:
On 25 August, 2017 Rohingya militants stage coordinated attacks on police posts in Myanmar's Rakhine state, killing at least a dozen officers.
The army retaliates with operations in Rohingya villages ostensibly to flush out insurgents.
It says it killed 400 rebels but opponents say most of the dead were civilians.
The United Nations says at least 1,000 people lost their lives in the first two weeks of the military operations.
By 5 September more than 120,000 Rohingya have fled into Bangladesh, overwhelming its ill-equipped refugee camps.
Many speak of abuses by the army and ethnic Rakhine, who are majority Buddhist.
There are already at least 300,000 Rohingya in Bangladesh from previous waves of violence.
Suu Kyi breaks silence
International anger mounts against the Myanmar regime, including after soldiers are accused of burning Rohingya out of their homes, with some world leaders alleging "ethnic cleansing".
In her first statement on the crisis, Myanmar's civil leader Aung San Suu Kyi pledges on 19 September to hold rights violators to account but refuses to blame the army.
She says she is open to bringing some of the exiled Rohingya home pending a "verification process".
UN raises possible 'genocide'
Bangladesh and Myanmar on 23 November agree to start repatriating refugees.
But the UN High Commissioner for Refugees says conditions are not in place for their safe return and the process halts.
UN human rights chief Zeid Ra'ad Al Hussein on 5 December warns of possible "elements of genocide" and calls for an international investigation.
On 25 August, 2018 tens of thousands of Rohingya refugees stage protests to mark the first anniversary of their exodus.
UN investigators call for the prosecution of Myanmar's army chief and five other top military commanders for genocide, crimes against humanity and war crimes.
On 3 September two Reuters journalists accused of breaching Myanmar's state secrets law while reporting on a Rohingya massacre are jailed for seven years.
They are eventually released more than 500 days later on May 7, 2019.
International court investigates
On 18 September, 2018 the Hague-based International Criminal Court announces a preliminary probe into the Myanmar military's alleged crimes against the Rohingya.
In November an attempt to repatriate 2,260 Rohingya fails as they refuse to leave without guarantees for their safety.
On 20 December Myanmar forces carry out new "clearance operations" in Rakhine state after new attacks, with one incident blamed on Rohingya.
On 29 May, 2019 Amnesty International accuses Myanmar's military of committing "war crimes", extrajudicial killings and torture.
On 16 July Washington announces sanctions against Myanmar's army chief and three other top officers for their role in "ethnic cleansing".
On 5 August the UN calls for tougher sanctions against Myanmar's military.
About 3,500 Rohingya refugees are cleared to return home but none turns up to take the buses and trucks provided to transport them from 22 August.
On 16 September the UN says some 600,000 Rohingya remaining in Myanmar face a "serious risk of genocide". It iterates calls for Myanmar's referral to the ICC.