Coup Atlas Research Database
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15506291973AttemptedMilitary coup

Chile, 1973 — military coup attempt

Chile (CHL)South America, AmericasJune 29, 1973

Event Summary

On 29 June 1973 elements of an armored regiment of the Chilean Army, led by Lieutenant Colonel Roberto Souper, staged a coup attempt known as El Tanquetazo against the Popular Unity government of the socialist president Salvador Allende. Souper's tanks surrounded and fired on the La Moneda presidential palace and the Defence Ministry in central Santiago, killing around 22 people. But the rising had no coordination with other units, and it was put down within hours by loyalist troops under the constitutionalist army commander in chief General Carlos Prats, who personally confronted the rebels; Souper surrendered.

Allende, who broadcast a call for workers to defend the government, survived. Though the Tanquetazo failed, it was a turning point that let the conspirators gauge loyalties and the weakness of pro-government forces, and it is seen as a rehearsal for the successful coup of 11 September 1973 in which General Augusto Pinochet overthrew Allende and ended Chilean democracy.

Researched Details

Researched

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

Target identified in Coup Atlas research: President Salvador Allende survived the Tanquetazo, which loyalist troops crushed, but he fell in the September 1973 coup
RESEARCHED NAME
Key figures
Salvador Allende (president of Chile, target)
Roberto Souper (lieutenant colonel, coup leader)
Carlos Prats (loyalist army commander who put down the coup)

Sources

El Tanquetazo was an attempted coup on 29 June 1973 in which elements of an armored regiment led by Lieutenant Colonel Roberto Souper tried to overthrow the Popular Unity government of President Salvador Allende.
SOURCE REVIEWED Wikipedia, Tanquetazo open source ↗
Souper's regiment fired on buildings of the Chilean government in central Santiago with tanks and small arms, killing 22 people.
SOURCE REVIEWED Wikipedia, Tanquetazo open source ↗
Loyalist soldiers led by Army commander in chief General Carlos Prats successfully put down the coup within hours, and Souper and most of the soldiers surrendered.
SOURCE REVIEWED Wikipedia, Tanquetazo open source ↗
The Tanquetazo is considered to have weakened Allende's government and to have been a prelude to the successful coup of 11 September 1973 that brought Augusto Pinochet to power.
SOURCE REVIEWED Wikipedia, Tanquetazo open source ↗

Editorial Note

Date match to the 29 June 1973 Tanquetazo. Dataset codes it a military coup with leader unharmed, accurate for Allende who survived this attempt only to fall in the September 1973 coup. Well documented. First Chile record in the dataset run; the successful September 1973 coup is a separate base event.

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
15506291973
Albrecht/Koehler/Schutz (CAM) id
CAM-155-1973-06-29

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

Outcome and Target

Coup Atlas research identifies the target as: President Salvador Allende survived the Tanquetazo, which loyalist troops crushed, but he fell in the September 1973 coup.

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.

Luttwak

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

New York Times

“A Coup Aborted... but a Democracy Dead,” June 30, 1973

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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