In 1936 the Spanish Army had two distinct forces: The Peninsular Army and the Army of Africa. The Peninsular Army had 8,851 officers and 112,228 men. It was considered to be poorly trained force and on the outbreak of the Spanish Civil War over 40,000 men were on leave. It is estimated that 4,660 officers and 19,000 men joined the Nationalist forces in the struggle with the Republicans. Of the remaining 4,191 officers, around 2,000 supported the Popular Front government.
The Army of Africa was considered to be superior to the Peninsular Army. It consisted of those Spanish Army units based in Morocco. In 1936 the force numbered 34,047 men and was composed of regular Spanish Army units and the Spanish Foreign Legion.
On 19th July, 1936, General Francisco Francoassumed command of this force and organized its airlift to Spain. During the first two months of the war, around 10,500 men were flown across the Straits of Gibraltar by aircraft owned by the Luftwaffe. Others followed and the Army of Africa played an important role in gaining Nationalist control of South-Western Spain.
There were also two internal paramilitary police forces: the Civil Guard and the Assault Guard. The Civil Guard, an elite paramilitary police force, had 69,000 men and officers. It is estimated that 42,000 joined the Nationalists and 27,000 remained with the Popular Front government. The Assault Guard had around 30,000 men. Of these, only 3,500 refused to join the Nationalist uprising.
It is estimated that the Republican government retained the loyalty of about half the soldiers in the Spanish Army. However, only a small percentage of the officers refused to fight with the Nationalist Army. These were often members of the left-wing Union Militar Republican Antifascisca (UMRA).
Soon after the outbreak of the Spanish Civil War the Republican Army was about one-third larger than the Nationalist Army. However, by the time the rest of the Army of Africa arrived in mainland Spain, the figures were close to equal. In the early stages of the war, members of the Falange Española, Carlists and other right-wing political parties joined the Nationalist Army.
After the first few weeks of the war the Nationalist Army controlled in the north of Spain the provinces of Galicia, León, Navarre and large parts of Old Castile and Aragón. In the south they held Cádiz, Seville, Córdoba, Granada, Huelva and Cáceres. Overall, the Nationalists controlled about a third of the land in Spain.
In the summer of 1936 General Emilio Mola calculated that the Nationalist Army had 100,000 in the northern sector and 60,000 in the south. On 26th August, 1936, the Nationalist authorities introduced conscription. This enabled them to recruit some 270,000 men during the next six months.
In September 1936, Lieutenant Colonel Walther Warlimont of the German General Staff arrived as the German commander and military adviser to General Francisco Franco. The following month Warlimont suggested that a German Condor Legion should be formed to fight in the Spanish Civil War.
The initial force consisted a Bomber Group of three squadrons of Ju-52 bombers; a Fighter Group with three squadrons of He-51 fighters; a Reconnaissance Group with two squadrons of He-99 and He-70 reconnaissance bombers; and a Seaplane Squadron of He-59 and He-60 floatplanes.
General Hugo Sperrle was appointed commander of the Condor Legion in November 1936. His chief of staff was Wolfram von Richthofen, the cousin of the First World War flying ace, Manfred von Richthofen. Wilhelm von Thoma was placed in charge of all German ground troops in the war. The Condor Legion was initially equipped with around 100 aircraft and 5,136 men but by the end of the war over 19,000 Germans had fought alongside the Nationalist Army.
In December 1936, Benito Mussolini also began to supply the Nationalists with men and equipment. This included 30,000 men from the Blue Shirts militia and 20,000 soldiers serving with the Italian Army. In March 1937 these men were incorporated into the Italian Corps (CTV).
A new combined Nationalist general headquarters was established at Salamanca in October 1936. The following year in November 1937 General Francisco Francomoved it to Burgos. Franco also had a mobile headquarters, known as Terminus, that moved to enable senior officers to observe offensives or Nationalist areas under threat.
The performance of the Republican Army gradually improved throughout the war but the lack of experienced junior officers meant that they were rarely able to take full advantage of breaking through Nationalist frontlines. In the spring of 1938 the Republicans were unable to block the Nationalist drive to the Mediterranean. Republican forces were also badly beaten in Aragon and Catalonia and at the beginning of February 1939, they began crossing into France.
Members of the Republican Army that were captured were treated harshly. Volunteers, militia officers, political commissars, professional non-commissioned officers, and any soldier who was not a conscript were court-martialled for military rebellion.
By the end of the Spanish Civil War the total mobilized force for the Nationalists was over 1,020,000. Of these, 70,000 were killed and 300,000 wounded. The number of men in the Nationalist Army who were wounded or died of their wounds, has never been published.