Coup Atlas Research Database
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78002171966ConspiracyMilitary coup

Sri Lanka, 1966 — military coup conspiracy

Sri Lanka (LKA)South Asia, AsiaFebruary 17, 1966

Event Summary

This entry is coded 17 February 1966, corresponding to the alleged 1966 Ceylonese coup, derisively called the Bathroom coup, against the government of Prime Minister Dudley Senanayake. Senanayake's United National Party had won the March 1965 election, ousting Sirimavo Bandaranaike, and his government began rolling back some pro-Sinhalese policies, to the resentment of certain factions in the security forces. While Senanayake was in Washington in February 1966 for medical treatment, the police, following an investigation led by CID director Ana Seneviratne, arrested several army non-commissioned officers, a retired civil servant and a politically connected Buddhist monk on the basis of an alleged plot to overthrow the government.

Army commander Major General Richard Udugama, a relative of Bandaranaike, was arrested later, on 7 July 1966. The prosecution collapsed when the Trial-at-Bar jury unanimously acquitted all the accused for lack of evidence, and the episode discredited the Senanayake administration.

Researched Details

Researched

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

Target identified in Coup Atlas research: Senanayake's government survived; the accused were all acquitted and the case damaged the administration's reputation
RESEARCHED NAME
Key figures
Dudley Senanayake (prime minister, target)
Maj. Gen. Richard Udugama (army commander, arrested and acquitted)
Ana Seneviratne (CID director who led the investigation)

Sources

While Dudley Senanayake was in Washington, the police, following investigations led by CID Director Ana Seneviratne, arrested several army non-commissioned officers, a retired civil servant and a monk with political ties on the basis of an alleged plot.
SOURCE REVIEWED Wikipedia: 1966 alleged Ceylonese coup attempt open source ↗
The commander of the army and several military personnel were arrested but were later acquitted of a plot to overthrow the legally elected government.
SOURCE REVIEWED Wikipedia: 1966 alleged Ceylonese coup attempt open source ↗
Army commander Major General Richard Udugama was arrested on 7 July 1966 at Katunayake Airport upon returning from the United Kingdom.
SOURCE REVIEWED Grokipedia: 1966 alleged Ceylonese coup attempt open source ↗
When Dudley Senanayake left for America in February 1966, it was a private visit as a patient to the Walter Reed Hospital, where he met Dean Rusk and Lyndon Johnson.
SOURCE REVIEWED Ilankai Tamil Sangam: Sri Lanka, The Untold Story, ch. 21 open source ↗

Editorial Note

Coded 17 Feb 1966 aligns with the February 1966 arrests made while Senanayake was in Washington; the army commander's arrest came later in July 1966. Verified as an alleged plot; all accused were ultimately acquitted, and the case is widely regarded as politically motivated.

Cross-Reference

Only one dataset carries it. One of the three reference datasets we check against carries this event; the others do not list it. That is not a contradiction — the datasets cover different periods and use different thresholds — but it means the record has had less outside corroboration.

Identifiers for finding this same event in the other datasets:

Cline Center id
78002171966

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

Outcome and Target

Coup Atlas research identifies the target as: Senanayake's government survived; the accused were all acquitted and the case damaged the administration's reputation.

Baseline coding: Plot discovered and disrupted before execution. 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

Wikipedia

Times of India

“New Break-through in Ceylon’s coup probe,” April 18, 1966
“Ceylon Coup bid probe in London with Army Chief,” June 15, 1966

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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