[Excerpt] There is a long and well established tradition of studies analysing the pattern and causes of internal migration and assessing the degree of labour market integration in late nineteenth-century Britain. Some studies document the flows of migrants from one area to another and describe migrant characteristics and the directions of the predominant streams of migration. Others analyse the determinants of gross or net migration flows at the region or county level. The questions implicit in these studies are: How mobile was the labour force? What were the major factors which determined individual decisions to migrate? How are these factors reflected in differences in migration flows between regions and in the pattern of long distance and short distance migration? Did labour mobility increase during the nineteenth century? There is also a strand of the literature which studies the effects of migration and labour mobility on the growth of industries, cities, and regions and above all on wage rates and wage differentials. The questions here are: How far did migration serve to integrate labour markets within and between regions and sectors? Do movements in regional and sectoral wage rates provide evidence of labour market integration? Did the degree of integration increase during the nineteenth century? In this article we provide a framework within which these questions can be addressed and which links together these two separate strands of the literature. Some of the existing literature is reviewed within this framework, and new evidence offered on the questions raised above. The article is organized as follows. In section I a simple framework is set out which stresses the links between migration and labour market integration. In section II the evidence on the character of migration flows, their magnitude and direction is examined. Section III focuses on the determinants of migration flows at the county level, particularly from rural southern counties. This is followed, in section W, with an examination of the effect of rural-urban migration on agricultural wage rates. Section V considers the evidence on regional labour market integration, and is followed by a brief conclusion summarizing the results.