Mercian was a language spoken in the
Anglo-Saxon kingdom of
Mercia (roughly speaking the Midlands of England an area in which four kingdoms had been united under one monarchy). Together with
Northumbrian, it was one of the two
Anglian dialects. The other two dialects of
Old English were
Kentish and
West Saxon. Each of those dialects was associated with an independent kingdom on the island. Of these, all of
Northumbria and most of
Mercia were overrun by the Vikings during the 9th century. Part of Mercia and all of
Kent were successfully defended but were then integrated into Wessex. Because of the centralisation of power and the Viking invasions, there is little or no written evidence for the development of non-Wessex dialects after Alfred's unification, until the Middle English period.