A native origin for Present-Day English they, their, them

It is commonly held that Present-Day English they, their, them are not descended from Old English but derive from the Old Norse third-person plural pronouns peir, peira, peim. This paper argues that the early northern English orthographic and distributional textual evidence agrees with an internal trajectory for the 'p-' type personal pronouns in the North and indicates an origin in the Old English demonstratives pa, para, pam. The Northern Middle English third-person plural pronominal system was the result of the reanalysis from demonstrative to personal pronoun that is common cross-linguistically in Germanic and non-Germanic languages alike.