The breakup of Spanish armed forces of July 1936 was the process of decomposition of the Second Spanish Republic's military and public order formations into two factions: the one which supported the government (loyalists, later called Republicans) and the one which joined the coup (rebels, later called Nationalists). Theoretically there were some 250,000 men serving in various armed branches. However, in fact this figure was probably much closer to 170,000, of which 90,000 served in the military and 80,000 in public order formations; detailed figures advanced by historians differ.
In historiography the prevailing opinion is that more armed servicemen joined the rebels than the loyalists; the ratio advanced differs from 62:38 to 52:48, yet there are also scholars who claim that only the minority joined the insurgency. It is usually accepted that slightly more peninsular troops and slightly more public order men remained loyal rather than rebelled, but that the so-called Army of Africa, which in its entirety joined the coup, tilted the balance in favor of the Nationalists.
Numerical split of manpower between the two warring sides of the Spanish Civil War is by no means indicative as to division of military and combat potential. This is mostly because in the Republican zone the effectives theoretically available were not taken advantage of; many military units were dissolved as potentially rebellious, many officers were detained, many units with few officers and NCOs left turned into loose undisciplined groupings, many rank-and-file servicemen opted for a wait-and-see stance and many later crossed to the Nationalist zone. Also, in early days following the failed coup the military potential of both sides was to a significant extent defined by civilian volunteers.
Military
The Spanish military forces were falling into 3 major groups: 1) mainland army, stationed in garrisons in peninsular Spain and on the islands; in numerical terms it was composed mostly of conscripts. Most scholars do not hold these troops in high regard, suggesting poor quality of training, low morale, outdated equipment and officers who often have never seen combat, resembling bureaucrats in uniforms rather than military commanders. These troops were organised into 8 so-called organic divisions, each corresponding to one military region; their theoretical strength is usually quoted as 110,000-120,000, but in July 1936 there were no more than 70,000 actually in the barracks; 2) army stationed in Africa. It consisted of heterogeneous formations, but mostly of indigenous Moroccan troops and the Foreign Legion, both composed of volunteers. Most of its officers and NCOs saw combat during Rif Wars. African troops were widely considered the best part of the Spanish army; they numbered some 24,500 men in actual service; 3) the navy. In terms of manpower there were some 12,000 people serving in its ranks; the fleet was composed of rather obsolete larger warships and numerous newer destroyers, with some modern cruisers near completion in shipyards. Peninsular and African troops were governed by the Ministry of War; the fleet was governed by the Ministry of Marine. Air force, which technically formed a separate branch, in terms of manpower grouped no more than few thousand men.there were some 250 military pilots in service, Hugh Thomas, Historia de la guerra civil española, Barcelona 1977, , p. 360; the rest were mechanics, other ground specialists and contracted civilians
Peninsular army
Beevor claims that there were some 110,000 military on the continent and islands in total;Antony Beevor, Walka o Hiszpanię, Kraków 2009, , p. 126 Alía Miranda opts for 115,000,for the year of 1935 he gives the figure of 114,642 men under arms, Francisco Alía Miranda, Julio de 1936: Conspiración y alzamiento contra la Segunda República, Barcelona 2011, , p. 41 while QuesadaAlejandro de Quesada, The Spanish Civil War 1936–1939 (1). Nationalist Forces, London 2014, [Men-at-Arms series by Osprey], p. 9 and Cliffordbut notes that only 80,000 were actually available, „The Peninsula Army had around 8,500 officers and 112,000 enlisted men, almost all poorly trained conscripts, 40,000 of whom were on leave”, Alexander Clifford, The People's Army in the Spanish Civil War. A Military History of the Republic and International Brigades, 1936–1939, London 2020, , p. 66 give the theoretical figure of 120,000. These figures stand no comparison to calculations of military historians, who claim that de facto there were some 65,000 troops in all peninsular garrisons;Lucas Molina Franco, Pablo Sagarra Renedo, Óscar González López, El factor humano. Organización y liderazgo para ganar una guerra. La Jefatura de Movilización, Instrucción y Recuperación en la Guerra Civil española, Madrid 2021, , p. 52 retrospective analysis of the Francoist staff claimed 60,000.Stanley G. Payne, The Spanish Revolution, New York 1970, , p. 315; the same figure in Frances Lannon, The Spanish Civil War, Oxford 2022, , p. 30 Fairly recent analysis of the Republican army during the civil war, written by Alpert, claims that the total number of troops actually in the barracks in July 1936 was some 65,000.Michael Alpert, The Republican Army in the Spanish Civil War, 1936–1939, Cambridge 2013, , p. 19 The record high figure of some 80,000 is suggested by Hooton and Clifford,Hooton says exactly 77,800; it is not stated explicitly, yet it emerges clearly as delta between all troops (113,800) and African troops (36,000), E. R. Hooton, Spain in Arms. A Military History of the Spanish Civil War 1936-1939, Oxford 2019, , p. 1. In case of Clifford, the figure of 80,000 is neither explicit, but it emerges from his other numbers, see Clifford 2020, p. 66 while the record low figure is advanced by Puell de la Villa, who gives the total of 45,000.Fernando Puell de la Villa, Julio de 1936: ¿Un ejército dividido?, [in:] Jorge Martínez Reverte (ed.), Los militares españoles en la Segunda República, Madrid 2012, pp. 77-98, referred after pdf version, pp. 16-17 How this mass was split between the Republicans and the Nationalists is unclear, e.g. at times totals advanced by various authors do not match their own sub-totals.Quesada claims that on paper there were 120,000 in the peninsular army, but 40,000 enjoyed leave, which leaves 80,000 in the barrackes. However, when doing detailed calculations for warring parties, he arrives at the peninsular total of only 47,000, compare Quesada 2014, p. 9, and Alejandro de Quesada, The Spanish Civil War 1936–1939 (2). Republican Forces, London 2015, [Men-at-Arms series by Osprey], p. 11 Cierva claimed 32,000 Republicans and 19,000 Nationalists (63:37),Ricardo de la Cierva, Historia de la guerra civil española, Madrid 1969, vol. 1, p. 69 Nationalist staff had 36,500 Republicans and 23,500 Nationalists (61:39),Payne 1970, p. 315 Quesada claims 33,000 Republicans and 24,000 Nationalists (58:42)Quesada 2015, p. 11, Quesada, 2014, p. 10 and exactly the same figures are given by Turnbull,Patrick Turnbull, The Spanish Civil War, London 1995, [Men-at-Arms series by Osprey], pp. 5, 7 Beevor settles for 57,000 Republicans and 50,000 Nationalists (53:47),Beevor 2009, p. 126 Romero Salvado opts for 35,000 Republicans and 32,000 Nationalists (52:48)Francisco Romero Salvado, Historical Dictionary of the Spanish Civil War, London 2013, , pp. 55-56 and almost exactly the same figures are advanced by Alpert, 34,000 Republicans and 32,000 Nationalists (52:48),Alpert 2013, p. 19 repeated also by ThomasHugh Thomas, The Spanish Civil War, London 2012, , p. 315 and Platón.at least with regard to Nationalists, Miguel Platón, Así comenzó la guerra civil, Madrid 2024, , p. 594 The same proportion of 52:48, but much lower totals are advanced (with detailed figures broken down into divisions and branches) by Arzanegui: 27,000 Republicans vs. 25,000 Nationalists.Alberto Arzanegui, El ejército español en 1936, [in:] El Miliciano 1 (1993) Hooton comes out with 40,000 Republicans and 38,000 Nationalists (51:49)exactly 39,800 Republicans and 38,000 Nationalists, subtotals not stated explicitly, but clearly emerging from other numbers given, Hooton 2019, p. 1 and same ratio, though different totals (46,000 Republicans, 44,000 Nationalists) are recommended by Ranzato,Gabriele Ranzzato, The Spanish Civil War, New York 1999, , p. 13 while Payne maintains that “less than half” of “fewer than 90,000” rebelledStanley G. Payne, The Spanish Civil War, Cambridge 2012, , p. 77 (47,000 Republicans, 38,000 Nationalists?). Some scholars, who accept the figure of 66,000 troops actually in the barracks on the peninsula, settle for general remark that they were “spread roughly equally”.Judith Keene, Fighting for Franco, London 2007, , p. 27 Puell is the only scholar who claims that most peninsular troops joined the rebels: 21,600 Republicans vs. 23,600 Nationalists (48:52).Puell 2012, pp. 16-17 In structural terms, out of 8 divisional commands 3 were controlled by the Republicans (I: Madrid, III: Valencia, IV: Barcelona) and 5 by the Nationalists (II: Sevilla, V: Zaragoza, VI: Burgos, VII: Valladolid, VIII: La Coruña). Out of 71 peninsular garrisons which hosted at least a battalion, the coup triumphed in 37 locations; 34 remained loyal.though 8 of the loyalist garrisons were in fact all either in Madrid or its suburbia (Madrid, Aranjuez, Getafe, Leganés, El Pardo, Carabanchel, Vicalvaro and Alcalá de Henares). Numbers based on a map in Antonio Nadal Sánchez, Málaga, 18 de julio de 1936, [in:] Jábega 21 (1978), p. 31. Slightly different geography is suggested in a map available at Desperta Ferro magazine website
African army
Some earlier works, e.g. Salas, claimed that the Army of Africa consisted of some 47,000 troops;Molina, Sagarra, González 2021, p. 51, also Ranzato 1999, p. 13 also some recent books advance similar figures, e.g. Beevor“The nationalists’ greatest military asset was the 40,000 men of the Army of Africa, with its combat experience”, Beevor 2009, p. 126 and CasanovaJulian Casanova, The Spanish Civil War, Cambridge 2009, , p. 24 refer to 40,000; Hooton claims 36,000Hooton 2019, p. 1 while PuellPuell 2012, p. 16 and ThomasThomas 2012, p. 315 give the number as 30,000. However, there was no homogeneous formation known as “Army of Africa” and Spanish Morocco was garrisoned by at least 4 different formations: 1) Foreign Legion, 2) indigenous troops in Spanish service, so-called Regulares, both infantry and cavalry, 3) indigenous troops in service of the sultan and 4) Carabineros, plus 5) minor figures related to navy, air force and policing formations. Already some older studies claimed that there were merely 24.5 thousand troops available to the Nationalists in Morocco,Payne 1970, p. 315 and the figure of 24,741 is advanced also by the recent military analysis.Molina, Sagarra, González 2021, p. 51 The difference, apart from usual issues related to leaves and outdated documentation, is due to some categories, especially troops in sultan's service, formally not having been under Spanish command and not having been available for shift towards the peninsula. All sources agree, however, that troops brought to Spain from Morocco were the best units in the army, battle-hardened during the Rif Wars, well-equipped and with high combative spirit. Almost all of these 25 thousand men joined the Nationalists, with the exception of some 300 men on leave on the peninsula.Payne 1970, p. 315
Navy