The town of Morpeth is in Northumberland, a market center on the River Wansbeck serving the surrounding rural areas and the villages of the Northumbrian coalfield. It evolved around a Norman fortress called Morpeth Castle, one of several guarding the east coast routes to Scotland. The "Morpeth Rant" was the name of a dance that has been performed for over almost two centuries and numerous tunes and tune variants were played in accompaniment to it over many years; thus there are a number of tunes called "Morpeth Rant" or "Old Morpeth Rant" that have varying degrees of similarity. One version is also used as a morris dance tune.
I learned this from Alec Slater's Clawhammer Banjo Solos book.