 Many historians are convinced that the Tribal Hidage originated from Mercia, which dominated southern Anglo-Saxon England until the start of the 9th century, but others have argued that the text was Northumbrian in origin.The Tribal Hidage has been of great importance to historians since the middle of the 19th century, partly because it mentions territories unrecorded in other documents.Attempts to link all the names in the list with modern places are highly speculative and all resulting maps are treated with caution.