The International Commission on Mathematical Instruction (ICMI) studies are unique in that they create opportunities to bring together large numbers and a diver-sity of scholars across countries and all kinds of practitioners to discuss a particular topic and generate publications deemed important and useful for different commu-nities. An international study on school mathematics curriculum reforms, some might argue, is overdue given its long history and given that it is a practice engaged by a large number of countries, states or regions around the world.Typically, ICMI Studies are commissioned when there is a considerable scholar-ship in particular area and the studies serve to pull these together in providing a ‘state of the art’ discourse on a particular topic and to shape the direction going forward. This ICMI Study 24 is especially singular in that while school mathemat-ics curriculum reforms are a widespread and enduring practice internationally and globally, as the Study Conference (Shimizu & Vithal, 2018) revealed, its in-depth study is arguably less so in comparison with, say, ICMI Study 23 on primary math-ematics study on whole numbers or ICMI Study 22 on mathematics task design.This became particularly evident to the International Program Committee (IPC) as a search was undertaken for leading mathematics education scholars in the broad area of school mathematics curriculum reforms to provide keynotes and plenary lectures for the conference. That is to say, there are a number of leading mathemat-ics educators participating in or even leading major school mathematics curriculum reforms in their countries, (many of whom participated in the study conference), but arguably a dearth of scholars or researchers in school mathematics curriculum reforms in the traditional sense of expert scholars with a wealth of publications about mathematical reforms. In fact, it would appear that those mathematics educa-tors involved in, say, national school mathematical curriculum reforms seldom seem to develop an extensive and deep scholarship of the intense practice of the curricu-lum reform itself that they engaged in driving, leading or participating.