Question: who led the army that defeated the aztecs
[{'answer': 'Hernán Cortés', 'provenance': [{'wikipedia_id': '5865939', 'title': 'Spanish conquest of the Aztec Empire', 'start_paragraph_id': 2, 'start_character': 93, 'end_paragraph_id': 2, 'end_character': 106, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]