text: Later history and end Despite the comparative obscurity of the kingdom, there were strong connections between Essex and the Kentish kingdom across the river Thames which led to the marriage of King Sledd to Ricula, sister of the king, Aethelbert of Kent. For a brief period in the 8th century the kingdom included west Kent. During this period, Essex kings were issuing their own sceattas (coins), perhaps as an assertion of their own independence. However, by the mid-8th century, much of the kingdom, including London, had fallen to Mercia and the rump of Essex, roughly the modern county, was now subordinate to the same. After the defeat of the Mercian king Beornwulf around AD 825, Sigered, the last king of Essex, ceded the kingdom which then became a possession of the Wessex king Egbert.
  The Mercians continued to control parts of Essex and may have supported a pretender to the Essex throne since a Sigeric  witnessed a Mercian charter after AD 825. During the ninth century, Essex was part of a sub-kingdom that included Sussex, Surrey and Kent. Sometime between 878 and 886, the territory was formally ceded by Wessex to the Danelaw kingdom of East Anglia, under the Treaty of Alfred and Guthrum. After the reconquest by Edward the Elder the king's representative in Essex was styled an ealdorman and Essex came to be regarded as a shire.
  List of kings
  The following list of kings may omit whole generations.