This thesis examines the emergence of the Irish Catholic diaspora in the industrial diocese of the West Riding of Yorkshire, and the evolution of the West Riding's forgotten Irish rugby clubs, 1860-c 1920. In addition to considering the contributions of Irish immigrants in the history of rugby football this thesis explores their religious, nationalist, social and cultural experiences, set within the wider history of Irish immigration in England. The history and establishment of parochial and non-parochial Irish Catholic rugby clubs in the West Riding can be traced back to the 1870s. Diasporic Irish Catholics settled in the county have always been part of rugby football since it's inception, albeit, at a much slower and punctuated rate than that observed among English Protestant communities. The foremost aim of this thesis is to scrutinise the rugby antecedents of Irish Catholics domiciled in the manufacturing centres of the West Riding during the Victorian and early Edwardian periods. In the late nineteenth century, towns and cities across the West Riding had become the great citadels of rugby football. Rugby attracted much participation, giving rise to the Catholic Church establishing its own internalised parochial rugby clubs, which were intended to improve the spiritual and physical well-being of its poor Irish adherents. This thesis, moreover, examines the establishment of non-parochial Irish rugby clubs which acted as sporting auxiliaries to Irish nationalist clubs. Finally, this thesis investigates those opportunities which allowed some working-class Irish Catholics to participate in games of rugby league outside of their own ethno-religious clubs for some of the county's senior professional rugby clubs. Since the main objective of Irish nationalist organisations was to offer financial support and political muscle to the Irish Parliamentary Party, this thesis will argue that the establishment of non-parochial nationalist Irish rugby clubs initially centred on the sport's by products, "gate-money"