Coup Atlas Research Database
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80009091985AttemptedMilitary coup

Thailand, 1985 — military coup attempt

Thailand (THA)Southeast Asia, AsiaSeptember 9, 1985

Event Summary

On 9 September 1985 a faction of former and cashiered Thai military officers attempted a coup against the government of Prime Minister Prem Tinsulanonda, striking in the pre dawn hours while Prem was abroad in Indonesia and the army commander was in Sweden. The attempt, sometimes called the Share Rebellion, was led by Colonel Manoon Roopkachorn, a veteran of the earlier 1981 Young Turks coup, and his brother, and was backed by several disgruntled former commanders including the ex prime minister Kriangsak Chomanan. Several hundred rebel troops with about twenty two tanks seized key sites in Bangkok, including a radio station and the army headquarters area, and fighting broke out in the streets.

But the coup collapsed within about ten hours: loyalist forces under deputy army chief General Chavalit Yongchaiyudh, using a radio station the rebels had failed to secure, rallied the army and persuaded or forced the rebels to surrender. Five people were killed, including two American NBC News journalists, and dozens of officers were arrested, while some ringleaders fled abroad. Prem survived and remained prime minister.

Researched Details

Researched

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

Target identified in Coup Atlas research: Prime Minister Prem Tinsulanonda's government crushed the September 1985 coup attempt within hours while he was abroad
RESEARCHED NAME
Key figures
Prem Tinsulanonda (prime minister of Thailand, target, abroad at the time)
Manoon Roopkachorn (colonel, coup leader)
Chavalit Yongchaiyudh (loyalist general who suppressed the coup)

Sources

The 1985 Thai coup attempt was a military coup attempt against the government of Prem Tinsulanonda by former military leaders on 9 September 1985, ended by a counter-coup the same morning that led to the surrender of the coup forces.
SOURCE REVIEWED Wikipedia, 1985 Thai coup attempt open source ↗
The pre-dawn coup, led by Manoon Roopkachorn and his brother and backed by former prime minister Kriangsak Chomanan, consisted of several hundred men and twenty-two tanks while Prem was abroad.
SOURCE REVIEWED Wikipedia, Manoonkrit Roopkachorn open source ↗
Within about ten hours government troops led by General Chavalit Yongchaiyudh quelled the rebellion, with 5 killed including two foreign journalists and over 40 officers arrested.
SOURCE REVIEWED Wikipedia, Manoonkrit Roopkachorn open source ↗
The coup attempt collapsed less than 12 hours after it was launched when military men loyal to Prem persuaded the rebels to surrender after skirmishes in downtown Bangkok.
SOURCE REVIEWED Washington Post, Coup in Thailand Collapses open source ↗

Editorial Note

Date match to the 9 September 1985 coup attempt. Dataset codes it a military coup with leader unharmed, accurate for Prem. Well documented. Fourth Thailand record in the run, after the 1977 Chalard and 1981 Young Turks coups; Manoon Roopkachorn links the 1981 and 1985 attempts.

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
80009091985
Albrecht/Koehler/Schutz (CAM) id
CAM-800-1985-09-09

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

Outcome and Target

Coup Atlas research identifies the target as: Prime Minister Prem Tinsulanonda's government crushed the September 1985 coup attempt within hours while he was abroad.

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
⚑ 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.

Wikipedia

https://en.wikipedia.org/wiki/Prem_T Insula Nonda#Overcoming_coup_attempts

New York Times

“THAILAND’S MILITARY SUFFERS SOME SELF-INFLICTED WOUNDS,” September 15, 1985

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 →

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