Guillaume I de Béthune

Guillaume I de was born about 1100.  Guillaume I de's father was Robert IV de Béthune and his mother was Alix de Péronne-Senlis.  His paternal grandfather was Robert III de Béthune; his maternal grandfather was Robert II de Péronne.  He was an only child.  He died in 1144.

‌Guillaume I de and Clémence d' were married in a religious ceremony in 1129.¹   They had a son and a daughter, named Robert V de and Mathilde de.