Guillaume Costiou
- Born on May 20, 1770 in Trédarzec
- Deceased before 1834
Parents
- François Costiou (1732 - 1776)
- Marguerite Le Quellec (1744 - 1774)
Family
- Married on October 7, 1814 in Hengoat, with Marie Yvonne Le Troadec (1776 - 1843), propriétaire, issuing
- Jouan (1815 - bef. 1875)