• Born: Between 1169 and 1170
• Married: 1184
• Died: 2 Feb 1193

  Research Notes:

Alternate death date: 6 Feb 1193.

The Chronologia Roberti Altissiodorenses records that "Guido comes" left two children by his wife "Mathildis", stating that they became wards of the king after their father died. "Matilidis comitissa" confirmed a previous donation to Cîteaux by "Agnes mater mea comitissa" for the soul of "patris mei Raimundi" with the consent of "filii mei Odo et Guillermus et Agnes et Ida" by charter dated 1179. Agnes must have been born soon after her parents' marriage as her own charter dated 1185 refers to her unnamed daughter.

She succeeded her brother in 1181 as Ctss de Nevers et d'Auxerre. "Matildis comitissa" donated property to Cîteaux for the souls of "Guidonis comitis Nivernensis, Petri Flandrensis et Odonis" with the consent of "filie mee Agnes…filia comitis Guidonis et Sibilla filia comitis Petri flandrensis" by charter dated 1182. The Chronologia Roberti Altissiodorenses records that "Philippus Rex" arranged the marriage of "Guidonis Comitis filiam" and "Petro patrueli suo", and installed him as Comte de Nevers. "Petrus comes Nivernensis et Agnes comitissa uxor eiusdem comitis et filia Guidonis comitis" confirmed the privileges of the church of St Etienne, Nevers by charter dated 1185.

She succeeded as Ctss de Tonnerre when she and her husband bought Tonnerre from her mother in 1191. "Petrus comes Nivernensis et Agnes comitissa uxor eius" agreed to renounce rights previously held by their predecessors, naming "Willelmus comes sepultus in ecclesia sancti Germani Autissiodonrensis…et filius eius Villelmus qui in Bethleem requiescit", in favour of Saint-Cyr by charter dated 10 Jun 1190.

The necrology of the abbey of Saint-Denis records the death "Non Feb" of "Agnes Nivernensis comitissa". ¹