ESP is a dynamic research discipline, underpinned by the fundamental question of how best to meet the needs of English learners, especially in our increasingly globalized and internationalized world. Since the early 1960s, ESP has become one of the most prominent areas of teaching in universities around the world. What began as a grass-roots solution to the need for vocationally-relevant English language education has evolved into a much broader field of research and application. Today, ESP plays a critical role globally evidenced by the massive growth of higher education institutions offering English-medium instruction (EMI), a conversation which must include the dichotomous approach of Content and Language Integrated Learning (CLIL). ESP has found its place as an essential way-point in the foreign language learning continuum in EMI contexts. As students advance their knowledge in their fields of study, so must they continue to acquire the English to help them understand and articulate vocational concepts, thus giving prominence to ESP. Yet, as this volume argues, there is a significant gap between implementation and assuring quality of ESP offerings, stemming from teachers' own incompetence and the lack of materials for specific contexts, as well as a lack of opportunities for ESP teachers to develop professionally and personally. This chapter reflects upon the evolution of this field from its roots to its current context. Through chapter-by-chapter synopses, it also presents an overview of the volume's central premise that quality ESP instruction does and can exist.