While global citizenship education (GCE) is becoming increasingly popular, it is also a complex and ambiguous concept that assumes different meanings. This article explores the dominant discourses that construct GCE in terms of the qualification, socialization and subjectification functions of education. Based on a qualitative study that used constructivist and informed grounded theory, the article focuses on the emergence of GCE in the educational discourse of the Province of Trento in northern Italy. The article shows elements of convergence and divergence between the perspectives of policymakers and teachers, and illustrates how in the discourses the three purposes of GCE -- qualification, socialization and subjectification -- are deeply intertwined and overlapping.