This book concludes that the English pronouns they, their, them are not Old Norse loanwords but derive from Old English demonstratives like þā and its variants. This change was an internally motivated paradigmatic merger, originating in the North and Southwest (Midlands). While intense language contact with Norse speakers reinforced and accelerated this native development in the northern dialects, the study establishes clear morphosyntactic and phonological continuity from Old English, reframing the pronouns’ history in the North as one of convergence, not replacement. In the Southwest (Midlands), dialect contact is likely to have fostered the increased use of ‘þ-’ type they, but its roots lie in local usage.