The segregated nature of the Victorian city was simply caused by social class. Cultural origins played an important role. Most obvious were the Irish, but European immigrants especially Jews, also formed cohesive and distinctive communities in many towns.
There had been considerable Irish migration to Britain before the 1840s, with well-established Irish communities in London and the west coast towns. It was the famines of the 1840s that brought a flood of destitute Irish to mainland Britain and helped to create images that were to persist throughout this period. After 1850 migrants were heavily concentrated in ports like London, Liverpool, Cardiff, Bristol and Glasgow and this position had changed little by 1891 though there had been some diffusion into a wider range of towns offerings employment opportunities.
- The majority of famine Irish was poor Catholics but the Irish community in Britain also included wealthier Catholics and Protestant Irish from Ulster. They formed quite distinct communities, yet images of poverty, Catholicism and nationalism tend to dominate the picture. In most cities the Irish-born were highly concentrated in specific locations yet, within the community, there were distinctive residential patterns: Protestants and Catholics in adjacent but separate areas and segregation between Irish of different social classes.
- Most Catholic Irish migrants were poor and dominated the employment statistics in towns with a large Irish population. They tended to have low status occupations and live in low-cost housing. However, this view needs to be seen against the fact that in all towns the Irish were found in all social groups and occupations.
- There have been various studies that attempt to assess the reasons for Irish residential concentration. As with other immigrants, clustering can be explained by a combination of economic and cultural reasons. Most obviously, poor Irish were constrained to live in low-cost housing areas in older central and industrial areas of cities. Within such areas many Irish seemed to cluster for cultural reasons: a grouping of Irish Catholics in a few courts provided mutual support for a religion that was still widely despised and suspected.
The Irish community in mainland Britain was a focus of both political and popular attention, fuelled by the growing political crisis in Ireland and the identification of Catholic Irish with its Nationalist cause. Although the volume of new migrants decreased after 1890, the Irish urban communities were united by their common experiences: their sense of common origin, their common experience of poverty and their perceptions of discrimination. Assimilation into English society proved difficult when cultural identity was such a central feature in their existence.
 R.Swift and S.Gilley (eds.) The Irish in the Victorian City, Croom Helm, 1985 contains some seminal essays on the Irish in relation to politics and religion. This can be supplemented with the collection of papers they edited The Irish in Britain 1815-1939, Pinter, 1989 and Steven Fielding Class and Ethnicity: Irish Catholics in England 1880-1939, Open University, 1993.