Coup Atlas Research Database
← Back to explorer
85010011965AttemptedMilitary coup

Indonesia, 1965 — military coup attempt

Indonesia (IDN)Southeast Asia, AsiaOctober 1, 1965

Event Summary

In the early hours of 1 October 1965 a group of Indonesian army officers calling itself the 30 September Movement kidnapped and killed six senior generals in Jakarta, claiming it was acting to forestall a rightist Council of Generals coup against President Sukarno. The movement, led by Lieutenant Colonel Untung and linked to figures around the Communist Party, briefly seized the radio station and Merdeka Square and announced it held Sukarno under its protection. But it was poorly led, ignored the strategic reserve headquarters, and by the end of the day General Suharto, commander of the army's strategic reserve, had rallied loyal forces and crushed it in the capital.

Sukarno refused to endorse the movement and initially remained the nominal president, but the army blamed the Communist Party and unleashed a nationwide anti-communist purge that killed hundreds of thousands. Over the following months Suharto eclipsed Sukarno, taking effective power in 1966 and the presidency by 1967.

Researched Details

Researched

Independent research, added record by record. Hover any label for what it means.

Target identified in Coup Atlas research: President Sukarno refused to back the movement and remained nominal president, but real power passed to Suharto over the following months
RESEARCHED NAME
Key figures
Sukarno (president of Indonesia, nominal figure the movement claimed to protect)
Untung (lieutenant colonel, movement leader)
Suharto (strategic reserve commander who crushed the movement and rose to power)

Sources

The 30 September Movement was a self-proclaimed organization of Indonesian armed forces members who, in the early hours of 1 October 1965, assassinated six Indonesian Army generals in an abortive coup, and by the end of the day the coup attempt had failed in Jakarta.
SOURCE REVIEWED Wikipedia, 30 September Movement open source ↗
The movement announced it had seized power to forestall a coup against the president by a council of generals, but General Suharto, commander of the army's strategic reserve, seized the initiative from the conspirators.
SOURCE REVIEWED Britannica, September 30th Movement open source ↗
President Sukarno went to Halim air base and eventually rejected giving his support to the movement, and Suharto, alongside Nasution and other officers, suppressed it in Jakarta.
SOURCE REVIEWED Wikipedia, 30 September Movement open source ↗
The army leadership insisted the movement was a PKI plot and purged the country of communists in mass killings, after which Sukarno came under increasing pressure and the army forced him to delegate powers to Suharto.
SOURCE REVIEWED Britannica, September 30th Movement open source ↗

Editorial Note

Date match to the 1 October 1965 killings, extensively documented. Dataset codes it a military coup and leader remained in office, reflecting Sukarno's survival as nominal president in the immediate aftermath before Suharto's gradual takeover. One of the most historically consequential entries in the dataset, triggering the 1965 to 1966 mass killings.

Cross-Reference

Datasets agree. At least two of the three reference datasets we check against carry this event, and none of them disagrees about its date or its result.

Identifiers for finding this same event in the other datasets:

Cline Center id
85010011965
Albrecht/Koehler/Schutz (CAM) id
CAM-850-1965-10-01

How the match is made is described in crossref-report.md.

Outcome and Target

Coup Atlas research identifies the target as: President Sukarno refused to back the movement and remained nominal president, but real power passed to Suharto over the following months.

Baseline coding: Coup attempt failed to remove the incumbent. Recorded leader fate: remained in office; not physically harmed. The baseline file does not name individual targets; researched names are kept in a separate layer.

Baseline Dataset Citation
Cline Center Coup d’État Project Dataset, v2.2.2
Peyton, Buddy, Joseph Bajjalieh, Michael Martin, and Andrea Gerald. 2026. Cline Center Coup d’État Project Dataset. Cline Center for Advanced Social Research. V.2.2.2. February 17. University of Illinois Urbana-Champaign. doi: 10.13012/B2IDB-9651987_V10
Open dataset DOI ↗
⚑ This citation establishes the coded baseline record; use the claim-level sources above for the researched narrative.

Baseline Source-Document Entries

CSP

Named in the baseline source document; no article citation was recorded.

Luttwak

Named in the baseline source document; no article citation was recorded.

Wikipedia

en.wikipedia.org/wiki/Sukarno

New York Times

“WASHINGTON AWAITS CLARIFICATION OF INDONESIAN SITUATION,” by Jack Raymond, October 2, 1965

This is the citation trail carried by the baseline dataset, grouped by outlet and rejoined from the line-wrapped original. Coup Atlas has not independently re-checked every document; read the original before citing a specific claim. URLs the import damaged beyond safe repair are shown as plain text and listed in citations-report.md. How this list is built →

Know something about this event?
Tips are reviewed against sources before anything is added.

Related Records

Indonesia — Military coup, 19521952-10-17AttemptedSoutheast AsiaIndonesia — Military coup, 19661966-03-12SuccessfulSoutheast AsiaIndonesia — Military coup, 19691969-12-19ConspiracySoutheast Asia