Since the “process” of contemporary devolution first began in 1998 three issues have often given lawyers, academics and critics food for thought. The first issue is external to the settlement: the relationship between devolution and parliamentary sovereignty. The ability of either to the survive the existence of the other has been a central question for the discourse, with both sovereignty and devolution potentially posing a death-knell for the other. The second issue is internal to the settlement: the tension between, on the one hand, the immensely technical nature of the devolution statutes themselves and, on the other, their profound constitutional significance. The former has sometimes served to obscure the latter from view. It would be curious, however, given that “[t]he carefully chosen language in which these provisions are expressed is not as important as the general message that the words convey”, for the technicalities of the Scotland Act 1998 to stand in the way of its constitutional “message”. The third issue was how best to make sense of that message, and to situate it within the constitution more generally. However, it is probably fair to say that the constitutional significance of the settlement itself is, unlike in its earlier years, no longer uncertain. Few would contend now that the devolved legislatures deserve comparisons with an English Parish Council. Curial attestations of the constitutional value of the devolved legislatures abound, a value which is predicated by their democratic credentials and reinforced in Scotland and Wales by legislative declarations of permanence, and in Northern Ireland by recourse to popular sovereignty. Yet, this constitutional status is by no means a panacea when a court is confronted with technical points of law, as the Supreme Court was in the Treaty Incorporation References case. Indeed, this case highlights the significance of the three issues outlined above and the Court’s conclusions about each of them are telling as to its understanding of both devolution itself, and its relationship with the wider the constitution.