Which steam locomotive was used to haul the "Hogwarts Express" in the "Harry Potter" film series?

5972 Olton Hall is a preserved Great Western Railway Hall class locomotive made famous for its role hauling the "Hogwarts Express" in the "Harry Potter" film series.

Built in April 1937 at Swindon Works for the Great Western Railway (GWR), No. 5972 was first allocated to Carmarthen, South Wales where it remained until 1951. After being fitted with a three row superheater at Swindon Works, it was allocated to Plymouth Laira. Its last shed allocation was to Cardiff East Dock, before it was withdrawn in December 1963, and sold to Woodham Brothers, Barry for scrap in May 1964.

Woodham Brothers sold the locomotive to David Smith and it moved to Horbury railway works in Wakefield in May 1981. In 1994, it moved to Carnforth MPD for restoration, being steamed for the first time in 1998.

In the "Harry Potter" films, the locomotive is depicted pulling the "Hogwarts Express", a fictional train, made up of four (later five) British Rail Mark 1 carriages. Scenes were filmed at King's Cross railway station, the Glenfinnan Viaduct and the North Yorkshire Moors Railway — along with internal scenes on board the train.