William, Lord of Coucy

Sir Guillaume I de Coucy (died 1335) was a 14th-century French nobleman. He was Lord of Coucy, Oisy, La Fère, Marle and Montmirail.

Biography Guillaume was the son of Enguerrand V de Coucy and Christine de Lindsay.

Marriage and issue Guillaume married secondly Isabelle, daughter of Guy IV de Chatillon and Marie de Bretagne, they are known to have had the following known issue.

Enguerrand VI de Coucy (died 25 August 1346), Lord of Coucy, Marle, La Fère, Oisy and Montmirail, married Katharine of Austria, had issue. William II de Coucy (died 6 February 1342), Lord of Wyresdale, Lancashire and other lands in England, married Joan de Strother, died without issue. Jean de Coucy (died c.1357), Lord of Havrincourt, without issue. Raoul de Coucy (died 1389), Lord of Montmirail, La Ferté-Gaucher, Encre and Bailleul, married Jeanne de Harcourt, had issue. Aubert de Coucy, Lord of Drosnay, Droizy and Romeny, married Jeanne de Villesavoir, had issue. Guy de Coucy, died without issue. Jeanne de Coucy, married Gaucher de Chatillon, Vicomte de Blaigny; had issue: Marguerite de Coucy Catherine de Coucy Marie de Coucy Isabelle de Coucy