At the end of the 9th century, following the invasions of the Vikings and their Great Heathen Army, much of the former Mercian territory was absorbed into the Danelaw.
9. sajandi lõpuks, pärast viikingite ja nende Suure paganate armee sissetunge, neelati enamus endisest Mercia territooriumist Danelaw'sse.