Atahualpa, Atahuallpa, Atabalipa ( in hispanicized spellings) or Atawallpa (Quechua) (20 March 1497–29 August 1533) was the last Sapa Inca (sovereign emperor) of the Tawantinsuyu (the Inca Empire) before the Spanish conquest. Atahualpa became emperor when he defeated and executed his older half-brother Huáscar in a civil war sparked by the death of their father, Inca Huayna Capac, from an infectious disease (possibly smallpox).