 Peter Featherstone has concluded that the original material, dating from late 7th century Mercia, was then used to be included in a late 9th century document and asserts that the Mercian kingdom "was at the centre of the world mapped out by the Tribal Hidage".Frank Stenton acknowledged that the evidence is not conclusive when he noted that "the Tribal Hidage was almost certainly compiled in Mercia".In contrast to most historians, Professor Nicholas Brooks has suggested that the list is of Northumbrian origin, noting that it would account for the inclusion of Elmet and the absence of the two Northumbrian kingdoms of Deira and Bernicia.