Kingdom of Essex
List of kings

Reign
Incumbent
Notes
527 to 587
(perhaps) Æscwine or Erchenwine
First king according to some sources, others saying son Sledd was first
587 to ante 604
Sledd
Son of Æscwine/Erchenwine
ante 604 to 616/7?
Sæberht
Son of Sledd
616/7? to 623?
Sexred
Son of Sæberht. Joint king with Saeward and a third brother; killed in battle against the West Saxons
616/7? to 623?
Saeward
Son of Sæberht. Joint king with Sexred and a third brother; killed in battle against the West Saxons
616/7? to 623?
(another son of Sæberht name unknown)
Joint king with Sexred and Saeward; killed in battle against the West Saxons
623? to ante c.653
Sigeberht the Little
-
c.653 to 660
Sigeberht the Good
Apparently son of Sæward. Saint Sigeberht; Saint Sebbi (Feast Day 29 August)
660 to 664
Swithhelm
-
664 to 683
Sighere
son of a Sigeberht, probably 'the Good'. Joint-king with Sæbbi
664 to c.694
Sæbbi
Son of Sexred. Joint-king with Sighere; abdicated in favour of his son Sigeheard
c.694 to c.709
Sigeheard
Joint-king with his brother Swaefred
c.695 to c.709
Swæfred
Son of Sæbbi. Joint-king with his brother Sigeheard
c. 709
Offa
Joint-king during latter part of reign of Swæfred and perhaps Sigeheard
c.709? to 746
Saelred
Representing distant line descended from Sledd. Probably joint-king with Swaefbert
c.715 to 738
Swæfbert
Probably joint-king with Saelred
746 to 758
Swithred
Grandson of Sigeheard
758 to 798
Sigeric
Son of Saelred. Abdicated
798 to 812
Sigered
Son of Sigeric. Mercia defeated by Egbert of Wessex, sub-kingdom of Essex subsumed into Wessex; from 812 to about 825 held it only as dux.

Question: Who was the last king of Essex?
Answer: Sigered was the last king of Essex.