The late 7th century saw the kingdom of Mercia expand, absorbing the Hwicce by the late 8th century and eventually coming to dominate most of England, but the growth of Viking power in the later 9th century saw eastern Mercia fall to the Danelaw, while the western part, including the Birmingham area, came to be dominated by Wessex. During the 10th century Edward the Elder of Wessex reorganised western Mercia for defensive purposes into shires based around the fortified burhs established by his sister Æthelflæd. The Birmingham area again found itself a border region, with the parish of Birmingham forming part of the Coleshill Hundred of newly created Warwickshire, but other areas of the modern city falling within Staffordshire and Worcestershire.