Short answers, pulled from the story.
The Second Spanish Republic was Spain's democratic government from 1931 to 1939. It was proclaimed on the 14th of April 1931 after King Alfonso XIII went into exile, and it dissolved on the 1st of April 1939 after surrendering the Spanish Civil War to the Nationalist rebels led by General Francisco Franco.
The Second Spanish Republic was proclaimed on the 14th of April 1931, two days after municipal elections gave republicans a landslide victory. King Alfonso XIII left Spain for exile at the same time, and a provisional government formed under Niceto Alcalá-Zamora.
The 1931 Constitution ended Catholicism's status as the state religion and, through articles 26 and 27, imposed strict controls on Church property while barring religious orders from teaching. Pope Pius XI condemned the loss of Catholic civil liberties in his encyclical Dilectissima Nobis, and scholars have since described the constitution as one of the most anti-religious of the twentieth century.
The immediate trigger was the assassination of right-wing leader José Calvo Sotelo on the 13th of July 1936, killed by Guardia de Asalto officers led by Fernando Condés after the earlier killing of Lieutenant José Castillo by Falangist gunmen. Three days later, on the 17th of July 1936, army officers led an uprising in Spanish Morocco under Generals Francisco Franco and Emilio Mola, beginning the Spanish Civil War.
Historians estimate that around half a million people died in the Spanish Civil War, though the figure is disputed and some researchers have suggested as many as a million. Modern research has generally concluded that the lower figure, roughly 500,000, is the more accurate count.
Three successive Republican governments led the war effort: José Giral from July to September 1936, Francisco Largo Caballero of the PSOE next, and finally the socialist Juan Negrín. Negrín's government fell after a military coup led by Segismundo Casado, which ended Republican resistance and led to the Nationalists' final victory.