The offences of murder and manslaughter have been the subject of several Law Commission reviews in England and Wales but no wholesale reform. The two major difficulties with the law of murder have been the continuing commitment to the mandatory penalty and the impossibility of capturing culpability in a nuanced way through the mechanics of the mental element of ‘intention to cause death or serious bodily harm’. The long accepted solution to these difficulties has been the use of partial defences of diminished responsibility and provocation to reduce murder to manslaughter in some circumstances, despite the defendant clearly having satisfied the mental element. In 2006, the Law Commission proposed a new architecture of homicide offences which would have resulted in partial defence killings being in the second of three categories of killing. This would have located them in the same bracket as killings accompanied by either intention to cause serious injury or an intention to cause injury coupled with a serious risk of causing death. Rather than adopt this new scheme, the government fast tracked reform of partial defences but retained the current bifurcation between murder and manslaughter. While diminished responsibility was retained, albeit cast in slightly different terms, provocation was replaced by a defence of ‘loss of control’. In this chapter we analyse these changes, in addition to the statutory consolidation of the law of self-defence, and point up the continuing incoherence and confusion in this area.