The causes, dynamics and results of the Sidónio Pais’s coup d’état (5–8 December 1917) in the First Portuguese Republic in the documents of the British War Cabinet
Authors:   Russian Timiryazev State Agrarian University, Mironiuk Sergei A. 
Published: October 2024

This article examines the coup d’état in the First Portuguese Republic, staged on 5–8 December 1917 by Major Sidónio Pais against the Government of Afonso da Costa and President Bernardino Machado. The author aims to uncover the causes, dynamics of events development and results of this coup d’état. The source base is the War Cabinet of Great Britain’s documents stored in the National Archive of the United Kingdom, which are being introduced into scientific discourse for the first time in the domestic historiography. The retrospective, systemic and narrative research methods were mainly used in the article. When using the retrospective method, it was established that the Sidónio Pais’s coup d’état was a logical result of the development of the First Portuguese Republic’s crisis. The systematic method revealed the constituent elements of this crisis: its political and socio-economic aspects, the consequence of which was mainly the coup d’état of Sidónio Pais. Since British documents had not been previously described in the domestic historiography, a narrative method was used in order to reflect fuller its content and character. The December 1917 coup d’état was the result of unsolved actual tasks after the establishment of the Republic in early October 1910 and accumulated problems after the Portugal’s entry into the First World War in March 1916. In peacetime, due to the radical anti-church policy, electoral restrictions, inter-party confrontation, changes of prime ministers and government compositions, it was difficult for the Republican leadership to solve consistently the urgent tasks in the country. In wartime, the internal situation had worsened and radicalized by December 1917 alone. The inability of the Republican leadership to solve the problems in the country and the short-sighted measures taken to improve the situation turned the majority of the civilian population and part of the military against it. In these conditions Artillery Major Sidónio Pais organized the coup d’état on 5 December 1917 with the aim of overthrowing the prime minister, leader of the Democratic Party Afonso da Costa and his fellow party member President Bernardino Machado. The coup d’état was accompanied by fierce fighting, especially in Lisbon. It ended on 8 December 1917 with the success of Sidónio Pais’s forces. Its results were the arrests of some members of the government, including the prime minister, and the president; the dissolution of the Portuguese Parliament – the Congress; the establishment of the Revolutionary Junta headed by Sidónio Pais, followed by the formation of a new government of the Republic. Thus, the December 1917 coup d’état was a response to the deep internal political crisis in Portugal. The documents of the British War Cabinet used in the study neither in general nor in detail contradict the facts set out in the historiography. However, they make it possible to expand possibilities for a further study of this coup d’état and related processes and events.