The early, non-hereditary counts

• Rodrigo (860–873),.^[5] He could have also been count in Álava^[6]
• Diego Rodríguez Porcelos (873–885)^[7]
• Munio Núñez (c.899–c.901)^[8]
• Gonzalo Téllez (903), mentioned only once, in 903, as Count of Castile. He was also count in Cerezo and Lantarón^[9]
• Munio Núñez (again, c.904–c.909)^[8]
• Gonzalo Fernández of Castile (c. 912–c. 916), "...most probably Gonzalo was Count of Burgos from 899 to 915 and, as from 912 until 915, also Count of Castile".^[10] He probably died after 915, when he still appears governing the county, and before 13 November 917 when a Fernando is recorded as Count of Castile.^[11]
• Ferdinand (917). Appears without a patronymic. Could have been Fernando Díaz, who on 8 January 918 confirms a charter as Fredinandus Didazi, comes, or Ferdinand Ansúrez who appears in 929 with this title.^[11]
• Nuño Fernández (c. 922–c. 926) On 13 September 922 appears as Count of Burgos and on 25 February 926 appears as Comite Nunu Fredinandiz in Castella.^[12] Although there is no documentary evidence, Nuño was probably the brother of Gonzalo Fernández of Castile.^[13]
• Ferdinand Ansúrez (c.926–c.929) Recorded as Count of Castile on 1 October and 24 November 929.^[13]
• Gutier Núñez (931), probably son of Nuño Fernández, appears as Count of Burgos on 1 March 931.^{[13][lower-alpha 2]}

Semi-autonomous, hereditary counts

Following the appointment of Fernán González in 931 to succeed both Gutier Núñez and Álvaro Herraméliz, he reunited the divided counties of Castile, Burgos, Álava, Cerezo and Lantarón into what would become a single semi-autonomous hereditary county of Castile.^[14] Al Andalus sources referred to the family as the Beni Mamaduna, the descendants of Muniadona de Lara, Fernán's mother.

• Fernán González (931–970), son of Gonzalo Fernández,^[15] married Sancha Sánchez, widow of Álvaro Herrameliz.^[16]
  • Ansur Fernández (944–947), son of Ferdinand Ansúrez,^[17] in opposition to Fernán González during the latter's rebellion,^[14] father-in-law of Sancho I of León
• García Fernández (970–995), son of Fernán González^[18]
• Sancho García (995–1017), son of García Fernández^[19]
• García Sánchez (1017–1029), son of Sancho García.^[20]

Jiménez Dynasty

With the death of Garcia Sánchez, the county of Castile passed to the family of his eldest sister, Muniadona of Castile, wife of Sancho III of Pamplona. Sancho thus became de facto ruler of Castile, though he was never its count,^[1] nominating his younger son to succeed Garcia.

• Ferdinand Sánchez (1029-1065), who continued to serve as count of Castile after he became king Ferdinand I of León.^{[lower-alpha 3]} On his death, Castile was elevated to a kingdom for his firstborn son, Sancho, who ruled as Sancho II of Castile.