JAN [I] van Peteghem (-1154 or before). His parentage is confirmed by the charter dated 1177 which records the approval by "Everardus…Tornacensis episcopus" of an agreement between Cysoing abbey and [his daughter] "Petronilla eiusdem ecclesie tunc temporis advocatrix", relating to their rights to use the forest of Cysoing, which refers to events in 1135, during the lifetime of "domino Ingelberto advocato", and after the death of "domno Ingelberto et Johanne filio eius" when "Petronilla eiusdem Johannis filia" inherited her father’s property[1362]. "Evrardus…Tornacensis episcopus" confirmed the donation by "Johannes advocatus Cisonii" to Cysoing, in the presence of "fratrum meorum Nicolai…de Avesnis et Gossuini advocati Tornacensis", by charter dated to [1174/86], confirmed after the donor’s death by "domna Petronilla uxor eius soror mea et Petrus supradicti Johannis frater"[1363]. m as her first husband, PETRONILLE d’Oisy, daughter of GAUTHIER [I] d’Oisy Seigneur d’Avesnes & his wife Ida de Mortagne (-after 1174). The Liber de Restauratione Sancti Martini Tornacensis records "quatuor filias [advocationem Tornacensem =Gualterus]" who were married, but does not name them[1364]. "Evrardus…Tornacensis episcopus" confirmed the donation by "Johannes advocatus Cisonii" to Cysoing, in the presence of "fratrum meorum Nicolai…de Avesnis et Gossuini advocati Tornacensis", by charter dated to [1174/86], confirmed after the donor’s death by "domna Petronilla uxor eius soror mea et Petrus supradicti Johannis frater"[1365]. She married secondly Roger de Landas. Jan [I] & his wife had two children