The Anglo-Saxon Kingdom was a group of kingdoms in England that existed from the 5th to 11th centuries. It was composed of four main kingdoms: Essex, Mercia, Wessex, and Sussex. Northumbria was also part of the kingdom. Essex was located in the southeast of England and was known for its strong military. Mercia was located in the Midlands and was the most powerful kingdom during the 8th century. Wessex was located in the southwest and was the last kingdom to remain independent from the Danes. Sussex was located in the south and was known for its strong economy. Northumbria was located in the northeast and was the largest kingdom in the Anglo-Saxon period.