This study examines Cambridge Assessment International Education (CAIE) as a global assemblage that instrumentalizes colonial governmentality. CAIE is a department of the University of Cambridge that has governed schools in British colonies and former colonies since the mid-19th century. These schools constitute a Cambridge School system with approximately 1 million students around the world who take Cambridge examinations. CAIE invisibilizes its thousands of schools in the global South by enclosing them within privatized discursive spaces it terms "Cambridge School Communities." CAIE simultaneously assembles and visibilizes an ecology of expertise by connecting a global array of researchers, consultants, businesses, organizations, publication outlets, and conferences. Rather than taking an interest in the "low-performing jurisdictions" of Africa, Latin America, and South Asia, CAIE's ecology of expertise positions British educational culture in relation to a pre-modern "East." CAIE explains the East's high performance in international comparative assessments with stereotypes in order to reassert the superiority of British-led international education. These technologies of colonial governmentality altogether enable CAIE's global extraction of epistemic authority.