Coup Atlas Research Database
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23503161974AttemptedMilitary coup

Portugal, 1974 — military coup attempt

Portugal (PRT)Southern Europe, EuropeMarch 16, 1974

Event Summary

On 16 March 1974 an infantry regiment based at Caldas da Rainha, north of Lisbon, mutinied and set out to march on the capital in a premature attempt to overthrow the Estado Novo dictatorship of Prime Minister Marcelo Caetano, the last such regime in Western Europe. The rising was organized by disaffected officers linked to the clandestine Armed Forces Movement, the network of captains who opposed the endless colonial wars in Africa. But the operation was underprepared and poorly coordinated; when a supporting rebellion at Lamego failed to materialize and other regiments held back, the column halted at Santarem and the Caldas da Rainha soldiers returned to barracks, where they were arrested.

Though the March 16 attempt failed, it was the direct dress rehearsal for the meticulously planned coup that the same movement carried out just weeks later. On 25 April 1974 the Armed Forces Movement overthrew Caetano in the almost bloodless Carnation Revolution, ending nearly half a century of dictatorship and launching Portugal's transition to democracy.

Researched Details

Researched

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

Target identified in Coup Atlas research: The Caetano regime suppressed the Caldas da Rainha uprising, but fell to the same movement's Carnation Revolution weeks later
RESEARCHED NAME
Key figures
Marcelo Caetano (prime minister of Portugal, target)
Caldas da Rainha regiment (mutineers)
Armed Forces Movement (MFA, organizers)

Sources

An infantry regiment in the town of Caldas da Rainha mutinied and attempted to march on Lisbon on 16 March 1974, but the uprising was suppressed the same day.
SOURCE REVIEWED IDEES, The United States, the CIA and 25 April 1974 open source ↗
On 16 March 1974 a group of about 200 soldiers headed by Armando Marques Ramos organized a failed military coup in Caldas da Rainha.
SOURCE REVIEWED Wikipedia, Carnation Revolution open source ↗
A military column left the Caldas da Rainha regiment bound for Lisbon, but a rebellion in Lamego made the other regiments unwilling to take the risk and the mission was aborted, after which the military returned to Caldas da Rainha and were arrested.
SOURCE REVIEWED Travel Tomorrow, Portugal's Carnation Revolution open source ↗
The Carnation Revolution of 25 April 1974 overthrew Marcelo Caetano and the Estado Novo regime, and the 16 March attempt is seen as having given the starting signal for the April revolution.
SOURCE REVIEWED Wikipedia, Carnation Revolution open source ↗

Editorial Note

Date match to the 16 March 1974 Caldas da Rainha uprising. Dataset codes it a military coup with leader unharmed, accurate for Caetano who survived this attempt but fell weeks later. Well documented as the prelude to the Carnation Revolution. First of three Portugal records in this batch, all from the 1974 to 1975 revolutionary period.

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
23503161974
Albrecht/Koehler/Schutz (CAM) id
CAM-235-1974-03-16

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

Outcome and Target

Coup Atlas research identifies the target as: The Caetano regime suppressed the Caldas da Rainha uprising, but fell to the same movement's Carnation Revolution weeks later.

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

The Globe and Mail

“Soldiers surrender: Portugal halts revolt over African policies,” March, 18 1974

Los Angeles Times

“DECORATED COLONEL HELD: Portugal Arrests 30 Officers After Revolt,” March, 18 1974

Washington Post

“Portugal Mutiny Put Down: Troops March, Protest Firing Of War Foe,” Miguel Acoca, March, 17 1974

The Austin American - Statesmen (1973-1980)

“Portugal Revolt Brings Arrests,”, March, 18, 1974

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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