The article examines the impact of inward Irish migration upon the small newly developing township of Birkenhead during the 1840s. It uses poor law records, census enumerators’ books, published Parliamentary Papers, Liverpool and Chester newspapers and the minutes of the Birkenhead Commissioners and the Parish Vestry to assess the short-term effects of the Irish immigration by focussing on settlement, disease, poverty and conflict. It analyses the available statistics to measure the concentration of Irish-born in different parts of the township, their vulnerability to disease and their possible contribution to the rising poor rate costs. This evidence is used to question the contemporary anti-Irish prejudice which the immigrants encountered. The article asks whether their social and economic conditions persuaded the Irish to engage in political conflict or if they were more likely to be motivated by religious motives.