Labour's Ted Rowlands, who has held this seat since 1972, recorded a majority of 27,086 over the Liberal Democrats in 1997.
Many parts of the UK claim to be the birthplace of the industrial revolution. Merthyr has as good a claim as any. The town was built first on iron and later coal. Its iron works at Cyfartha were at one time the largest in the world and the town can claim a notable list of other firsts. It had the world's first steam railway (pre-dating the Stockton and Darlington by some years). It saw the first raising of the red flag during a week long workers' uprising in 1832 and it later elected Keir Hardie - one of the founders of the Labour movement - its MP.
In the town of Merthyr itself little remains of the old industrial heritage. The town is dominated by a series of large council estates with high levels of unemployment and deprivation. To the south of Merthyr the constituency extends for ten miles along the floor of the Taff Valley, where the 1966 Aberfan disaster, when colliery waste engulfed the local junior school, is still an open wound.