At 10:37 AM on July 19, 1947, four armed men entered the Secretariat Building in Rangoon and opened fire on Burma's Executive Council. General Aung San — age 32, the architect of Burma's independence movement — was killed along with six cabinet members and two others. The gunman was U Saw, a former Prime Minister and political rival who had been detained by the British during World War II for attempted collaboration with the Japanese. U Saw confessed, was tried, and hanged within five months. But questions remained about who else knew, what British intelligence observed, and why key files remain classified eight decades later.
At 10:37 AM on July 19, 1947, General Aung San was chairing a meeting of Burma's Executive Council in Room 4 of the Secretariat Building in central Rangoon. The session was routine — budget discussions, administrative matters, the procedural work of preparing a colony for independence. Burma was scheduled to become a sovereign nation in less than six months. Aung San, at 32 years old, was the unquestioned leader of the independence movement and the presumptive first Prime Minister. Six other cabinet members sat around the table with him.
Four men carrying Sten guns entered through the main entrance. They encountered no security checkpoint. They walked up the stairs to the second floor. A civil servant passed them in the hallway and later testified he assumed they were military officers on official business. At 10:37, the four men pushed open the door to Room 4 and opened fire.
Aung San's body was taken to Rangoon General Hospital. His wife Khin Kyi arrived with their three children, including two-year-old Aung San Suu Kyi. Governor Hubert Rance declared a state of emergency and ordered the investigation that would lead to the trial, conviction, and execution of U Saw within 10 months. But the investigation left unanswered questions that persist eight decades later — particularly regarding what British intelligence knew before the attack and why key files remain sealed.
Aung San's path to that meeting room began in 1940 when he fled Burma as a wanted man. Born in 1915 in Natmauk, a small town in central Burma, he had been active in student politics at Rangoon University, helping to found the Dobama Asiayone (We Burmans Association) and adopting the honorific "Thakin" (master) — a direct challenge to the racial hierarchy of British colonialism. By 1940, he faced arrest for seditious activities. He left Burma secretly, made contact with Japanese military intelligence in China, and traveled to Tokyo.
The Japanese were preparing for southward expansion and saw utility in Burmese nationalists. They provided military training to Aung San and 29 other Burmese recruits — the group that would become known as the Thirty Comrades. When Japan invaded Burma in December 1941, Aung San returned at the head of the Burma Independence Army, fighting alongside Japanese forces against the British and Indian troops defending the colony.
But Japanese occupation proved as oppressive as British colonialism. By 1944, Aung San had made secret contact with British Force 136 and began planning a switch of allegiance. On March 27, 1945 — a date still celebrated in Myanmar as Resistance Day — Aung San's forces turned on the Japanese and fought alongside British forces for the remainder of the war. This pivot from collaboration to resistance gave Aung San unique credibility: he had fought the British, worked with the Japanese, then fought the Japanese and worked with the British. He could not be dismissed as a British puppet, nor could he be easily accused of collaboration after his 1945 turnabout.
"Aung San possessed the rare combination of military credibility and political pragmatism necessary to navigate the ethnic divisions and ideological conflicts of postwar Burma. His death removed the one figure capable of holding the independence coalition together."
U Nu — Saturday's Son: Memoirs of the Former Prime Minister of Burma, 1975After Japan's surrender in August 1945, Aung San transformed from military commander to political organizer. He founded the Anti-Fascist People's Freedom League (AFPFL), a coalition that united socialists, communists, ethnic minority groups, and other nationalist factions. In September 1946, Governor Rance appointed him Deputy Chairman of the Executive Council — effectively making him the head of Burma's proto-government. In January 1947, Aung San traveled to London and negotiated directly with Prime Minister Clement Attlee.
The result was the Aung San-Attlee Agreement, signed January 27, 1947. Britain committed to granting Burma full independence within one year. Elections would be held for a Constituent Assembly that would draft a constitution. Burma would control its own defense and foreign policy immediately. It was a remarkably swift transition compared to the protracted negotiations over Indian independence or the violence that would accompany partition in Palestine. Aung San returned to Rangoon in February 1947 as the architect of Burma's freedom.
U Saw represented everything Aung San had outmaneuvered. Born in 1900, U Saw came from Burma's old political class — nationalist, certainly, but conservative, tied to business interests, and willing to work within colonial structures for incremental reform. He had served as Prime Minister from 1940 to 1942 under British rule, a position that gave him legitimacy among moderates but tainted him in the eyes of radicals who saw any collaboration with the British as betrayal.
In November 1941, U Saw traveled to London to negotiate greater autonomy for Burma. On his return journey, he stopped in Lisbon — neutral Portugal — and allegedly made contact with Japanese representatives. British intelligence intercepted communications suggesting U Saw was exploring whether Japan might offer Burma better terms than Britain. In January 1942, as Japanese forces advanced into Burma, British authorities arrested U Saw in Palestine. He was detained for the remainder of the war in Uganda, held without trial under emergency wartime powers.
U Saw returned to Burma in 1946 to find the political landscape transformed. Aung San's AFPFL dominated. The independence movement had moved left — toward socialism, land reform, and rapid nationalization. U Saw founded the Myochit (Patriot) Party to represent conservative nationalism, but the 1947 Constituent Assembly elections delivered a crushing defeat. The AFPFL won 171 of 182 seats. U Saw's party won a handful. When the Executive Council was formed, U Saw was excluded entirely.
Witnesses would later testify that U Saw became increasingly desperate through the spring of 1947. He believed — correctly — that once independence was formalized, his political career was finished. Aung San would become Prime Minister. The AFPFL would control parliament. U Saw would be relegated to irrelevance. According to trial testimony, he began exploring other options.
In early July 1947, U Saw made contact with individuals who had access to British military equipment. Postwar Burma was flooded with surplus weapons. British and Indian Army units were demobilizing. Equipment was being inventoried, stored, and shipped. In the chaos, substantial quantities went missing. The black market thrived.
At U Saw's trial, prosecution witnesses testified that he purchased four Sten submachine guns and ammunition for 10,000 rupees. The Sten gun was standard British Army issue — a simple, cheap, mass-produced weapon used throughout World War II and postwar. The seller was identified as a British deserter with connections to military supply depots. The transaction occurred less than two weeks before the assassination.
Governor Rance's confidential report to London, filed July 20, 1947, noted the weapons' origin and raised immediate questions about security. How had British military equipment reached a political figure under intelligence surveillance? Were there failures in depot security, or did the transaction suggest something more organized? Rance requested a full audit of missing weapons and an intelligence assessment of who else might be armed.
The sealed portions of British intelligence files include assessments of U Saw's activities after his return from detention, communications between MI5 officers in Burma and London headquarters, and Governor Rance's intelligence briefings in the weeks before the assassination. Historians who have examined the declassified portions note that the redacted sections specifically concern "individuals under surveillance" and "sources and methods." The implication is that British intelligence was watching U Saw — but either failed to detect the conspiracy or detected it and failed to act.
The four gunmen arrived at the Secretariat at approximately 10:35 AM. They were dressed in civilian clothes but carried military-style firearms openly. A security guard later testified that he assumed they were part of an authorized unit and waved them through. They climbed to the second floor and proceeded directly to Room 4.
The cabinet meeting had begun at 10:00 AM. Present were Aung San as Deputy Chairman, Thakin Mya (Minister of Home Affairs), Mahn Ba Khaing (representative of the Karen minority), Ba Win (Minister of Trade and Development), Abdul Razak (Minister of Education), and several other officials. Two bodyguards, Ko Htwe and Ohn Maung, stood outside the room.
At 10:37, the gunmen pushed open the door. Ko Htwe and Ohn Maung attempted to intervene and were shot immediately. The four men entered the room and opened fire. Witnesses in adjacent offices heard sustained automatic fire for approximately 90 seconds. When the shooting stopped, nine people were dead or dying. The gunmen walked back down the stairs and out the main entrance. They dispersed into the street.
The immediate response was chaos. Secretariat staff fled the building. Other cabinet members who had been in different offices tried to secure the scene. Medical personnel arrived within minutes, but seven of the nine victims were dead before reaching the hospital. Governor Rance, who was in the building but not in Room 4, immediately declared a state of emergency and ordered all police and military units to begin searching for suspects.
By late afternoon, police had identified U Saw as the prime suspect. Witnesses had seen him meeting with individuals who matched the gunmen's descriptions. Informants provided information about the weapon purchase. U Saw was arrested at his home that evening. Over the next 48 hours, police detained his three accomplices and recovered two of the four Sten guns.
U Saw's trial began on October 27, 1947, in the Burma High Court. The prosecution case was straightforward: U Saw had organized and financed the assassination. He had recruited the gunmen. He had provided the weapons. Multiple witnesses testified to his statements of political desperation and his determination to prevent Aung San from becoming Prime Minister. The murder weapons were entered into evidence. Ballistics matched the recovered guns to casings from the scene.
U Saw's defense did not dispute the facts. Instead, his lawyers argued duress and claimed he had been manipulated by unnamed others who had their own motives for eliminating Aung San. U Saw hinted at British intelligence involvement, suggesting he had been set up to eliminate a leader London secretly opposed. He provided no evidence for these claims. His testimony was rambling and often contradictory.
On November 11, 1947 — 18 days after the trial began — U Saw and his three accomplices were convicted of murder. The judge sentenced all four to death by hanging. Appeals were filed and rejected. On May 8, 1948 — three months after Burma gained independence — U Saw was hanged at Rangoon's Insein Prison. His final words, according to prison records, were incoherent denials and accusations.
"U Saw went to his death claiming he had been used by British intelligence to eliminate Aung San. He never provided evidence. But he never stopped asking why the British had let him return to Burma after his wartime detention if they did not expect him to act against Aung San."
Thant Myint-U — The Hidden History of Burma, 2019The central question that remains unanswered is this: What did British intelligence know about U Saw's conspiracy, and when did they know it? The partially declassified files reveal that U Saw was under some form of surveillance after his return to Burma in 1946. MI5 maintained files on political figures considered potential security threats. U Saw — who had attempted to contact the Japanese in 1941 and spent four years in detention — would have been an obvious target for monitoring.
Governor Rance's communications with the Colonial Office in June and July 1947 remain partially redacted. The declassified portions discuss "potential for political violence" and "monitoring of opposition figures." The redacted portions, according to the National Archives index, concern "intelligence assessments" and "operational details." Freedom of Information requests filed in 1999, 2007, and 2017 have been rejected on grounds that disclosure would "harm national security" or "prejudice relations with foreign governments."
Historian Thant Myint-U, who has examined the declassified files extensively, argues that the pattern of redactions suggests British intelligence detected the conspiracy but failed to assess it as credible or imminent. In his 2019 book *The Hidden History of Burma*, he writes: "The British knew U Saw was desperate, bitter, and potentially dangerous. They knew he had access to funds and connections to the black market. But they appear to have dismissed him as a spent force — a former politician who posed no real threat. That assessment proved catastrophically wrong."
A darker interpretation is that British intelligence detected the conspiracy and chose not to intervene. This theory, popular among Burmese historians but disputed by British scholars, holds that elements within the British security establishment viewed Aung San as too socialist, too independent, and too close to potentially communist influences. Eliminating him before independence would allow a more moderate figure — someone like U Nu — to take power. There is no documentary evidence for this theory in the declassified files, but the very absence of evidence is suspicious to those who note how thoroughly other aspects of the independence period are documented.
What is documented is that Governor Rance was shocked by the attack and immediately ordered a full investigation. His July 20 report to London describes the massacre as "a catastrophic blow to Burma's independence process" and requests additional security resources and intelligence support. But the report also includes a telling sentence: "Questions must be asked about how this conspiracy evaded detection." The recipient responses to Rance's report — from the Colonial Office and intelligence services — remain classified.
Burma gained independence on January 4, 1948, as scheduled. U Nu became the first Prime Minister. But the country Aung San had imagined — multi-ethnic, federal, socialist but democratic — never materialized. Within months of independence, communist insurgencies erupted. Karen and other ethnic minorities, feeling marginalized by the Burman-dominated government, launched their own armed rebellions. The conflicts that began in 1948 have never fully ended.
U Nu served as Prime Minister until 1962, interrupted by military interventions and political instability. In March 1962, General Ne Win staged a coup and installed military rule that lasted, in various forms, until 2011. Burma became one of the world's poorest and most isolated nations, its initial promise crushed under decades of dictatorship.
The question that haunts Burmese history is whether Aung San could have prevented this trajectory. His political coalition was fragile, his socialist economic policies were untested, and the ethnic tensions that exploded after independence were already visible in 1947. But Aung San had unique credibility. He had fought the British, the Japanese, and then the Japanese again. He had military credentials and political vision. He had negotiated with ethnic minority leaders and persuaded them to join the independence project.
"Everything changed when Aung San died. He was the one person who could hold the country together. After him, there was no center. Only fragments pulling in different directions."
U Nu — Saturday's Son, 1975Aung San's daughter, two-year-old Aung San Suu Kyi at the time of his death, grew up in his shadow. Raised by her mother Khin Kyi, she studied at Oxford, married a British academic, and lived abroad for decades. In 1988, she returned to Burma to care for her ailing mother and found herself thrust into leading the democracy movement against military rule. The military placed her under house arrest for 15 years. She was awarded the Nobel Peace Prize in 1991 while detained. After her release and elections in 2015, she became State Counsellor, effectively leading the civilian government.
But Aung San Suu Kyi's tenure proved controversial. She defended the military's brutal treatment of the Rohingya minority. She failed to pursue democratic reforms or hold the military accountable. In February 2021, the military staged another coup and detained her. She has been convicted in military courts on various charges and sentenced to 33 years in prison. Her reputation internationally collapsed. The parallel with her father is painful: both reached the threshold of power, both promised transformation, both were stopped — one by assassination, one by her own choices and military intervention.
In 2017, historian Thant Myint-U filed a Freedom of Information request with the UK Foreign Office seeking full declassification of British intelligence files related to the July 19, 1947 assassination. His petition argued that 70 years had passed, all principals were dead, and the historical record deserved completion. The Foreign Office denied the request in May 2018, citing Section 23 (security bodies) and Section 27 (international relations) of the Freedom of Information Act.
The denial letter stated that disclosure would "risk undermining the security and intelligence agencies' capabilities" and could "damage relations with foreign governments and international organisations." It did not specify which foreign governments or what specific capabilities would be compromised by revealing what British intelligence knew about a 1947 political assassination in a former colony.
As of 2024, approximately 30% of the relevant files remain sealed. The National Archives catalog shows that files related to "Intelligence Assessments — Burma Political Figures 1946-1948" are closed until 2047 — a full century after the assassination. Other files are marked "Retained by Department" — meaning they have never been transferred to the National Archives and remain in the control of intelligence services.
What is known from the declassified portions is incomplete but suggestive. British intelligence maintained active surveillance on political figures in Burma through 1947. U Saw was monitored. Weapons movements were tracked. Governor Rance received intelligence briefings. But somewhere in the chain — detection, assessment, communication, response — the system failed. Whether that failure was incompetence or intention remains unknown. The files that could answer the question remain sealed.
On July 19, 1947, at 10:37 AM, four men with British-made weapons walked into Burma's Secretariat Building and killed the architect of Burmese independence. The gunmen were arrested, tried, convicted, and hanged. The case was closed. But the historical case remains open.
What is documented: U Saw organized the massacre. He obtained British military weapons through black market channels. He recruited and equipped four assassins. Nine people were killed. U Saw was executed in May 1948. These facts are established beyond dispute.
What remains unknown: Whether British intelligence detected the conspiracy before it unfolded. Whether officials in London or Rangoon knew U Saw was planning violence and failed to intervene. Whether the weapons reached U Saw through simple security failures or something more organized. Why key intelligence files from 1947 remain sealed in 2024. What those files contain.
Aung San's death changed Burma's history. The leader who might have held the country's fractious ethnic and political groups together was gone six months before independence. The violence that followed — ethnic insurgencies, communist rebellions, military coups, decades of dictatorship — might have been inevitable. Or it might have been preventable. The sealed files in London's archives might contain evidence relevant to that question. They might not. But as long as they remain sealed, the question remains open: What did British intelligence know about the assassination of Aung San, and why won't they tell us?