This chapter traces the evolution of ethical thinking in artificial intelligence, moving from early philosophical concerns to the development of binding regulatory frameworks. It examines foundational principles that shaped the ethics of AI, including fairness, transparency, and accountability, and explores how global initiatives have attempted to formalize these principles into enforceable norms. Through a review of major international guidelines and theoretical models, the chapter highlights the transition from voluntary ethical declarations to structured governance mechanisms. The analysis emphasizes the growing need for risk-based, context-sensitive approaches that bridge the gap between abstract values and real-world deployment. Ultimately, the chapter underscores that ethical AI must be grounded not only in principles but also in institutional responsibilities and legal obligations.