Abertillery is a town in the county borough of Blaenau Gwent and the traditional county of Monmouthshire in southern Wales, 16 miles north-west of Newport, originally on the Great Western Railway. Its population rose steeply during the period of mining development in the Rhondda valleys, being 10,846 in the 1891 census and 21,945 ten years later. It lies in the mountainous mining district of Monmouthshire and Glamorganshire, in the valley of the Ebbw Fach, and the population was traditionally employed in the numerous coalmines, ironworks and tinplate works, now defunct.