Self-determination is one of international law’s most reviled and yet most important principles. The legal development of self-determination – or specific forms thereof – as a customary norm of international law has been shaped and spurred by key moments. These include the American and French declarations of 1776 and 1789, the conclusion of the UN Charter, and the General Assembly’s resolution 1514 (xv) in 1960. This article analyses whether, in characterising the effect of such moments, the label ‘Grotian’ moment adds (...) meaningfully to the analysis. It concludes that the example of self-determination suggests that the ‘Grotian’ moment concept is not meaningfully illuminating; tending either to reduce to a slight of hand in favour of the so-called ‘Great Powers’, or alternatively to pathologise developments that would be amenable to standard forms of customary legal analysis. (shrink)