Now a county in the extreme southeast of England, Kent was an Anglo-Saxon Kingdom in its own right. As legend has it, the Jutes under Horsa and Hengist crossed into England in the 450's A.D.
Anglo-Saxon Rulers of Kent

This list would have gotten nowhere without the help of Eric Hall's excellent website on British heredity.

Hengist (455-488)
Aesc (Eric, Oisc) (488-512)
Octa (512-540)
Eormenric (540-560)
Aethelbert (560-616)
Eadbald (616-640)
Egbert (664-673)
Hlothhere (673-685)
Eadric (684-686)
Suaebard (jointly) 676
Oswini (688-690)
Wihtred (690-725)
Eadbert I and Alric (725-748)
Aethelbert II (735-762)
Heabehrt (765)
Egbert II (765-780)
Ealhmund (786, 788)
Eadbert II (794(6?)-796(8?))
Cuthred (798-807)
Baldred (807-825)

Kent, Surrey, and Sussex
King Egbert of Wessex pushed Baldred north across the Thames in 825. Kent became a kingdom, bundled with Surrey and Sussex, that a Wessex king with too many sons would give a second son:

Egbert (c.825-839)
Aethelstan (839-851?)
Aethelwulf (of Wessex) (851?-856)
Aethelbert (856-860)
Aethelbert succeeds to the throne of Wessex, 860 Kent overrun by the Danes, 865

The line of rulers of Kent continues in the node for Wessex, and then in the Rulers of England node.