This thesis assesses the origins, development and decline o f an industrial and landed powerbase at Milford, Co. Carlow, from 1790 to 1870. John Alexander I (1764-1843), a Protestant merchant from Belfast, arrived in Carlow in 1784 and, due to a combination o f protective government legislation and his own considerable commercial talent, had created the largest milling complex in Ireland by the 1840s. The infrastructures, activities, successes and beneficial socio-economic impact o f the mills saw Milford develop as a significant centre o f population in the county. The vast profits o f John Alexander & Co. enabled the Alexander family to achieve considerable social and political power. With their purchase o f a small landed estate, the Alexanders constructed a gentry identity among the county’s elite, rising to its upper echelons by 1853 — all the more surprising given Carlow’s traditional resistance to the social elevation o f the merchant community. The emergence o f Milford as a model landed estate enhanced the family’s reputation at a county and wider level. In making the claim that this ascent was remarkable, the foundations and mechanics o f this powerbase, as well as the tensions therein, are outlined. In the second generation, the Alexanders’ politics swung from a liberal paternalism to Tory self-protectionism in a bid to consolidate their privileged socio-political position. This set landlord and tenant at odds in Milford, and transformed the Alexanders’ fame into notoriety, with electoral controversies in the area receiving national and international attention. W ith the decline o f their milling supremacy (due to the repeal o f the Com Laws, accident and legal disputes), their social and political powers had been fundamentally undermined by 1870. Despite scholarly neglect, this thesis illustrates and analyses the A lexanders’ centrality and influence at a county, provincial and national level during this period.