Oswiu of Northumbria
A document called the Tribal Hidage may date from Wulfhere's reign. Drawn up before many smaller groups of peoples were absorbed into the larger kingdoms, such as Mercia, it records the peoples of Anglo-Saxon England, along with an assessment in hides, a unit of land. The Tribal Hidage is difficult to date precisely; it may have been written down in Wulfhere's reign, but other suggested origins include the reign of Offa of Mercia, or Edwin or Oswiu of Northumbria.