As an 18th century ‘standard of civilization,’ the Western liberal constitution has since been integral to public international law and colonial trusteeship. This book is the first comprehensive treatment of the ostensible purposes why international organizations have internationalized this Constitution: from the League of Nations in Danzig, to the UN starting from Libya in 1949, and from 1989-2018, in more than forty poor states including most recently in Colombia and The Gambia. This pioneering study sets the Constitution’s internationalization via United Nations Constitutional Assistance (UNCA) at centre-stage. The Constitution’s salience makes its post-1989 rise via UNCA the most significant post-Cold War development, one which has spawned and shaped all other legal and political developments. For example, the internationalization of this Constitution (subsumed under the ‘rule of law’ label) drives the famed post-1989 rule of law movement, shaping all sectors from electoral, judicial, security, and parliamentary to international criminal and transitional justice. This Constitution’s internationalization is traced, from France’s drafting of Turkey’s 1856 monetary laws, British lawyer, Travis Twiss’ drafting of Congo’s 1885 constitution to the constitutional assistance offered by the League of Nations during the inter-war period and from 1949, by its successor, the United Nations and through a combined historical international constitutional framework, UNCA’s legitimacy is appraised. Through this new constitutional history of trusteeship, Sripati demonstrates that creating an equitable order requires considering seriously why sovereign states’ constitution-making is being internationalized. The book concludes by arguing that UNCA continues its trusteeship role. UNCA makes a new fiscally oriented addition to the ‘standards of civilization’: ‘transparent, inclusive and participatory’ constitution-making.