Mercia
The ninth century saw the decline of Mercia as a kingdom. In 873-74 Mercia was conquered by the heathen army. In the 880s Wessex formed a marriage alliance with Mercia. Alfred's daughter, Aethelflaed , married Aethelred (II), of Mercia. When Aethelred died, in 912, Edward the Elder appointed Aethelflaed (his sister) 'Lady of the Mercians.' When Aethelflaed died in 918, the Mercian nobles now thought themselves free of Wessex rule. Edward stepped in and appointed Aethelflaed's daughter, Aelfwynn, to rule Mercia as his representative. But in 919 Edward brought her back to Wessex. After that Mercia was considered just another shire under his rule. A series of ealdormen (similar to a count in Europe) followed. Under Canute in 1017, Mercia became one of the four divisions of England.