In this Introduction we argue that every “tech revolution” in language teaching has revealed our beliefs about education and the teacher’s role within it, rather than solely providing instruments to enhance pedagogy. As we delineate and explore a trajectory from language labs and behaviourist Computer-Assisted Language Learning (CALL), through communicative and networked CALL, to mobile learning and the pandemic, we show how teachers’ work has gradually expanded from delivering content to also managing access, tools, care, and equity. Into this already stretched ecosystem arrive Large Language Models, which can generate fluent language but still lack communicative agency. Early research (2023–2025) shows that AI can support practice, feedback, and personalisation across multiple languages, including some work on minoritised languages, but it really risks reinforcing inequalities, perception of language ideologies and hierarchies, and ethical problems. We conclude arguing that AI is only educationally valuable when guided by informed, ethically grounded principles and practices, which sets up the rest of the volume to explore how language education can adopt AI without losing its human and intercultural core.