Parse this person name:

Christopher Richardson, 1421-1462, flourished 1439-1450
user
first_name: Christopher
last_name: Richardson
middle_names: []
temporal:
- start: 1421
  end: 1462
  type: life_span
- start: 1439
  end: 1450
  type: flourished
titles: []
extra_info: []
assistant