Civil war caused decline in the Inca empire in 1525, when ruler Huayna Capac died and his two sons, Atahualpa and Huascar, fought. Although Atahualpa won, his empire was weakened and he was no match for the Spaniards when they arrived from Europe. | Civil war caused decline in the Inca empire in 1525, when ruler Huayna Capac died and his two sons, Atahualpa and Huascar, fought. Although Atahualpa won, his empire was weakened and he was no match for the Spaniards when they arrived from Europe. |