Nationalist rebels attempted a coup against the Second Spanish Republic, sparking the Spanish Civil War.

The Nationalist faction, also Rebel faction and Francoist faction was a major faction in the Spanish Civil War of 1936 to 1939. It was composed of a variety of right-leaning political groups that supported the Spanish Coup of July 1936 against the Second Spanish Republic and Republican faction and sought to depose Manuel Azaña, including the Falange, the CEDA, and two rival monarchist claimants: the Alfonsist Renovación Española and the Carlist Traditionalist Communion. In 1937, all the groups were merged into the FET y de las JONS. After the death of the faction's early leaders, General Francisco Franco, one of the members of the 1936 coup, headed the Nationalists throughout most of the war, and emerged as the dictator of Spain until his death in 1975.

The Spanish coup of July 1936 was a military uprising that was intended to overthrow the Spanish Second Republic, but precipitated the Spanish Civil War, in which Nationalists fought against Republicans for control of Spain. The coup was organized for 18 July 1936, although it started the previous day in Spanish Morocco. Instead of resulting in a prompt transfer of power, the coup split control of the Spanish military and territory roughly in half. The resulting civil war ultimately led to the establishment of a nationalist regime under Francisco Franco, who became ruler of Spain as caudillo.

The Spanish Republic, commonly known as the Second Spanish Republic, was the form of democratic government in Spain from 1931 to 1939. The Republic was proclaimed on 14 April 1931 after the deposition of King Alfonso XIII. It was dissolved on 1 April 1939 after surrendering in the Spanish Civil War to the Nationalists led by General Francisco Franco.

The Spanish Civil War was fought from 1936 to 1939 between the Republicans and the Nationalists. Republicans were loyal to the left-leaning Popular Front government of the Second Spanish Republic and included socialists, anarchists, communists and separatists. The opposing Nationalists who established the Spanish State were an alliance of fascist Falangists, monarchists, conservatives, and traditionalists supported by Nazi Germany and Fascist Italy and led by a military junta among whom General Francisco Franco quickly achieved a preponderant role. Due to the international political climate at the time, the war was variously viewed as class struggle, a religious struggle, or a struggle between dictatorship and republican democracy, between revolution and counterrevolution, or between fascism and communism. The Nationalists won the war, which ended in early 1939, and ruled Spain until Franco's death in November 1975.