The event that led to the start of the Spanish Civil War in the 1930s was the military coup staged by General Francisco Franco in July 1936. This coup aimed to overthrow the democratically elected Second Spanish Republic, which faced internal strife and severe political division between the leftist republicans and conservative factions. The coup initially failed to achieve a swift victory, resulting in a prolonged and bloody civil war that lasted until 1939. The conflict attracted international attention and involvement, with various ideologies clashing, ultimately leading to Franco's dictatorship.