The Calder Valley constituency is a huge, rambling stretch of land that covers large areas of moor land on the eastern side of the Pennines.
It also has townships, first formed during the Industrial Revolution, when the damp climate and abundance of water power made the area ideal for the manufacture of woollen textiles - an industry that has all but disappeared nowadays.
The constituency follows the river Calder and its tributaries, as it winds south of Halifax, from the topmost town of Todmorden near the moors, down as far as Brighouse.
Labour won the seat by just 47 votes in 1959, and the Conservatives by 59 in 1970. Five changes in party allegiance have been recorded in this constituency over a thirty year span.
There was some disgruntlement amongst Labour supporters in this constituency on the Yorkshire/Lancashire boundary, when the preferred local candidate David Chaytor was forced to de-camp to Bury North, following the arrival of Christine McCafferty - a "Blair Babe" fresh from the party's all-women shortlist.
Nonetheless, Ms McCafferty, a former local councillor and social worker, beat the Tory incumbent Donald Thompson with a 9.5% swing to Labour and a winning margin in excess of 6,000 votes.