Simplify the following text for a Grade 6 native English-speaking person.
Original: The Kingdom of Wessex or Kingdom of the West Saxons was an Anglo-Saxon kingdom of the West Saxons , in South West England , from the 6th century , until the emergence of a united English state in the 10th century , under the Wessex dynasty .
Simplified: Wessex was an old Anglo-Saxon kingdom before England became one country .