Parse this person name:

Willem Vierdag, 1229-1290, flourished 1256-1275
user
first_name: Willem
last_name: Vierdag
middle_names: []
temporal:
- start: 1229
  end: 1290
  type: life_span
- start: 1256
  end: 1275
  type: flourished
titles: []
extra_info: []
assistant