Parse this person name:

Sigmar Hildburg H. Marit Siering-Holsten, died 1285
user
first_name: Sigmar
last_name: Siering-Holsten
middle_names:
- Hildburg
- H.
- Marit
temporal:
- start: null
  end: 1285
  type: life_span
titles: []
extra_info: []
assistant