The Kingdom of Essex or Kingdom of the East Saxons was one of the seven traditional kingdoms of the so-called Anglo-Saxon

Anglo-Saxons

Anglo-Saxon is a term used by historians to designate the Germanic tribes who invaded and settled the south and east of Great Britain beginning in the early 5th century AD, and the period from their creation of the English nation to the Norman conquest. The Anglo-Saxon Era denotes the period of...

 Heptarchy

Heptarchy

The Heptarchy is a collective name applied to the Anglo-Saxon kingdoms of south, east, and central Great Britain during late antiquity and the early Middle Ages, conventionally identified as seven: Northumbria, Mercia, East Anglia, Essex, Kent, Sussex and Wessex...

. It was founded in the 6th century and covered the territory later occupied by the counties

Counties of England

Counties of England are areas used for the purposes of administrative, geographical and political demarcation. For administrative purposes, England outside Greater London and the Isles of Scilly is divided into 83 counties. The counties may consist of a single district or be divided into several...

 of Essex

Essex

Essex is a ceremonial and non-metropolitan county in the East region of England, and one of the home counties. It is located to the northeast of Greater London. It borders with Cambridgeshire and Suffolk to the north, Hertfordshire to the west, Kent to the South and London to the south west...

, Hertfordshire

Hertfordshire

Hertfordshire is a ceremonial and non-metropolitan county in the East region of England. The county town is Hertford.The county is one of the Home Counties and lies inland, bordered by Greater London , Buckinghamshire , Bedfordshire , Cambridgeshire and...

, Middlesex

Middlesex

Middlesex is one of the historic counties of England and the second smallest by area. The low-lying county contained the wealthy and politically independent City of London on its southern boundary and was dominated by it from a very early time...

 and (for a short while) Kent

Kent

Kent is a county in southeast England, and is one of the home counties. It borders East Sussex, Surrey and Greater London and has a defined boundary with Essex in the middle of the Thames Estuary. The ceremonial county boundaries of Kent include the shire county of Kent and the unitary borough of...

. Kings of Essex were frequently subservient to foreign overlords. The last king of Essex was Sigered and in 825, he ceded the kingdom to Egbert of Wessex

Egbert of Wessex

Egbert was King of Wessex from 802 until his death in 839. His father was Ealhmund of Kent...

.
The kingdom was bounded to the north by the River Stour

River Stour, Suffolk

The River Stour is a river in East Anglia, England. It is 76 km long and forms most of the county boundary between Suffolk to the north, and Essex to the south. It rises in eastern Cambridgeshire, passes to the east of Haverhill, through Cavendish, Sudbury and the Dedham Vale, and joins the...

 and the Kingdom of East Anglia, to the south by the River Thames

River Thames

The River Thames flows through southern England. It is the longest river entirely in England and the second longest in the United Kingdom. While it is best known because its lower reaches flow through central London, the river flows alongside several other towns and cities, including Oxford,...

 and Kent

Kent

Kent is a county in southeast England, and is one of the home counties. It borders East Sussex, Surrey and Greater London and has a defined boundary with Essex in the middle of the Thames Estuary. The ceremonial county boundaries of Kent include the shire county of Kent and the unitary borough of...

, to the east lay the North Sea

North Sea

In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...

 and to the west Mercia

Mercia

Mercia was one of the kingdoms of the Anglo-Saxon Heptarchy. It was centred on the valley of the River Trent and its tributaries in the region now known as the English Midlands...

.