As early as 1936, the U.M.E. had made some attempts to create this climate. The commanders of two of the nine divisions of the Spanish regular army, General Miguel Cabanellas, of the 5th Division based in Zaragoza, and General Rafael Villegas, of the 1st Division stationed in Madrid, were implicated in the conspiracy whose chief the military governor of Pamplona, Brigadier General Emilio Mola. A key role in the plot was reserved for General Francisco Franco.
Franco was a soldier entirely devoted to his trade, renowned for his bravery and his insolent luck in battle. A brilliant organizer, a man of discipline and rigor, he had completely remodeled the Spanish Foreign Legion during the four years he commanded it, from 1923 to 1927, and had made it an extremely effective fighting force.
Moreover, very cautious, he only joined the conspirators quite late. The government, which considered him insecure, had assigned him to an unimportant command in the Canary Islands. But before taking office, Franco warned — with some brutality — the prime minister of the dangers of communism. The latter having replied that his remarks were absurd and unfounded, Franco then decided to join the military uprising, to "save Spain".
Mola's campaign plan was to seize the entire province of Navarre, then move towards Madrid with four assault columns launched in an arc, from north to northwest, against the capital. Franco was entrusted with a key role:to be recognized as commander-in-chief of the African army in Morocco, to lead it on Spanish soil and to march on Madrid from the southwest. Carefully laid plans were also made to ensure the neutrality of other generals who were fundamentally loyal to the government, albeit at odds with its policy, so that they could not interfere with the plan.
The rebellion coincidentally broke out a few hours earlier than expected on Friday, July 17, 1936, and instead of a planned and coordinated uprising across Spain, a succession of isolated coups took place over the next three days. Despite the slow and confused reactions of power, the Spanish people themselves thwarted the rebellion in many places. Madrid, Valencia and many other smaller towns resisted successfully; three of the Basque provinces, all of Catalonia and most of eastern Spain from the French border to Almeria remained loyal to the government.