Urbs Iudeu (Urbs Judeu/Ludeu) was a city, whose location is now unknown, which according to the ninth-century Historia Brittonum was besieged in 655 AD by Penda, King of Mercia, and Cadafael, King of Gwynedd.
The siege can be seen as an important episode in a long-running war between Mercia and Northumbria in the years 616–679. This war was fought in the area north of the River Trent, in particular in and around the Peak District (Wirksworth) also around Heathfield (Doncaster), Elmet (Aberford) and Lindsey (Lincoln), as these were provinces of Northumbria at the time.