This is from 1905, 30 December Leeds Mercury newspaper. I can’t guarantee it’s true, but it fits with a lot of similar stories, a sort of Chinese whisper in physical form.
“Very few, even of the residents of the town, know how Halifax got its name. According to ancient history, Halifax was formerly called Horton, and it is said that the name was changed in the following incident:
A secular priest of the village of Horton became violently enamoured of a young woman and his passion turned his brain. Happening to meet her in a retired spot, he murdered her, horribly mangled her body, and cut off her head. The head was afterwards hung upon a yew tree and soon became regarded with a superstitious veneration. It was frequently visited on a pilgrimage but at length, the head rotting away, the devotion of the vulgar was transferred to the tree, and so many branches were torn off, ad carried away as relics, that it was at length reduced to a bare trunk. This trunk succeeded to the honours of the tree, as the tree had succeeded to those of the head; and the devotees who still visited it conceived a not in that the sale fibres in the rind between the bark and the body of the tree, were in reality the very hairs of the young woman’s head. The is supposed miracle made the trunk anew object of devotion, ad the visits of the pilgrims were greater than ever, so that the place acquired the name of Haligflax, or Holy Hair, which by a little variation become Halifax, the present name.