The article compares men's biographies and fatherhood across two generations among the Irish and the Polish, who represent different waves of migration to Britain, focusing on two chains of fathers and sons. It examines different aspects of transmission between fathers and sons and, in the context of migration, the part that generational experience played in how men identify (or not) with their own fathers and repeated or changed their fatherhood practices. A comparative approach suggests the importance of taking account of the life course, the historical moment of migration, and the ways in which migration complicates intergenerational family relations by creating structural and relational ambivalences as the younger generation seeks to make its own mark. However ambivalences are managed and often coexist with solidaristic relations in terms of providing reciprocal support across the generations and in the fathers' identification with their fathers' strong work ethic and provider role. As fathers they are more involved in their children's lives than their fathers were but their employment conditions typically continue to constrain this.