Objective: This study examined the backgrounds of fathers who fatally abuse their children and the contexts within which these homicides occur. The type of relationship between victim, perpetrator, and the victim's mother was a particular interest. Methods: Data were gathered from 26 cases of fatal child abuse perpetrated by fathers derived from the wider Murder in Britain study. ****The Murder in Britain study was supported by an ESRC grant. Quantitative and qualitative data were collected from extensive prison case files of men serving life sentences for child murder. Results: This was a group of undereducated, underemployed men with significant criminal histories. All except one victim had been subjected to previous violence by the offender, almost three-quarter of whom had also perpetrated violence against their intimate partners (the child's birth mother). Many men had unreasonable expectations and low tolerance levels of normal childhood behaviors, and many appeared jealous and resentful of these young children. All 26 victims were under 4 years of age. Sixty-two percent of the offenders were stepfathers and in only four cases was the perpetrator a birth father married to the birth mother. Stepfathers had more disrupted and disadvantaged backgrounds and experiences than birth fathers. Conclusions: Findings suggest that fathers who perpetrate fatal child abuse have a propensity to use violence against children in their care and intimate partners, raising questions about the gender dynamics and generational boundaries operating in these families. The nature and type of intimate relationship (whether married or cohabiting) and fathering relationship (whether birth or de facto) were important differentiating factors in these homicides as well as characteristics of the offender. Practice implications: Professionals working in child protection strive to provide effective services to children and families, ever vigilant to the possibility of the death of a child as a consequence of an assault. By and large, fathers (either biological or de facro) as the perpetrators of such assaults have received minimal attention in both policy and practice. Findings from this study suggest that practitioners need to be cognisant of men's attitudes towards and excpeectations of fathering (particularly stepfathering) which may present increased levels of risk to both children and intimate partners. © 2007.