The County of Auxerre is a former state of current central France, with capital in Auxerre.
The first count attested by the sources is one Ermenaud, a companion of Charlemagne who reigned around 770. In 859 Charles the Bald handed over the county to his cousin Conrad II of Burgundy. When he revolted, the county was assigned to Robert the Strong. After the latter's death, Hugh the Abbot was count, but named a viscount in his lieu; later Auxerre was absorbed in Richard of Burgundy's dominion.
It returned to the Capetians with Renauld I of Nevers. Auxerre remained part of Nevers until 1262. It was sold to the King of France in 1370. After the Treaty of Arras (1435) between Charles VII of France and Philip III of Burgundy, it returned once again to the latter. In 1477, with the annexion of Burgundy, it became definitively part of France.
Ermenaud I of Auxerre c. 758
Ermenaud II of Auxerre ?
Ermenaud III of Auxerre c. 840
Jouvert of Auxerre c. 853
Adelaide I of Auxerre (daughter) 853–864
Conrad I of Auxerre, duke of Transjuran Burgundy 859–864 (married to Adelaide)
Robert the Strong 864–866 (married to Adelaide) (king
Conrad II of Auxerre (son) 853–876
Hugh the Abbot (son of Adelaide) 876–886
Adelaide II of Burgundy (daughter of Conrad I) 921–936
Richard of Gorze 886–921 (married with Adelaide II)
Raoul I of Gorze (son) 821–936
To France 936–971
Heribert of Auxerre 971–996 (son of Hugh the Great, dux francorum)
Eudes Henri of Auxerre (halfbrother) 996–1002
Adelaide of Auxerre (daughter of king Robert II of France), countess of Auxerre
Renauld I of Nevers (son of Landri, lord of Monceaux and Maers) 1031–1040 count of Auxerre (married to Adelaide)
William I, Count of Nevers (son) 1040–1083 (count of Auxerre, Tonnerre and Nevers)
Renauld II of Nevers (son) 1083–1089 (count of Auxerre and Nevers)
William II, Count of Nevers (son) 1097–1148 (count of Auxerre, Tonnerre and Nevers)
William III, Count of Nevers (son) 1148–1161 (count of Auxerre, Tonnerre and Nevers)
William IV, Count of Nevers (son) 1161–1168 (count of Auxerre, Tonnerre and Nevers)
Guy I of Nevers (brother) 1168–1175 (count of Tonnerre, Auxerre and Nevers)
William V, Count of Nevers (son) 1175–1181 (count of Auxerre, Tonnerre and Nevers)
Agnes I of Nevers (sister) 1181–1192
Peter II of Courtenay 1184–1218 (married to Agnes)
Mahault I of Coutenay (daughter) 1218–1257
Hervé of Donzy 1218–1257 (married to Mahault)
Agnes II of Donzy (daughter) 1218–1225 (deceased before her mother)
Guy II of Châtillon, count of Saint Pol 1223–1225 (married to Agnes II)
Gaucher of Châtillon (son) ? (deceased)
Yolande of Châtillon (daughter) ?–1254
Archambaud of Dampierre ?–1254 (Archambaud IX Lord of Bourbon) (married to Yolande)
Mahaut of Dampierre (daughter) 1257–1262
Odo of Burgundy 1257–1251 (married to Mahaut)
Alix of Burgundy (daughter) 1251–1290
John I 1273–1290 (married to Alix, joint rulers)
William VI the Great (son) 1290–1304
John II (son) 1304–1361
John III (son) 1361–1370
John IV (son) 1370
Sold to France 1370