Question: when did the viking great army arrived in england
[{'answer': 'AD 865', 'provenance': [{'wikipedia_id': '3779598', 'title': 'Great Heathen Army', 'start_paragraph_id': 1, 'start_character': 280, 'end_paragraph_id': 1, 'end_character': 286, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '3779598', 'title': 'Great Heathen Army', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 286, 'bleu_score': 0.612969534028965, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11448369947291276783}, 'section': 'Section::::Abstract.'}]}]