This document discusses the evolution of instructional leadership as a concept in school administration over the past 30 years. It began as a focus on the principal's role based on research in the 1980s, but faced criticism and was later eclipsed by ideas of transformational and teacher leadership. However, increased accountability has led to a renewed global interest in instructional leadership, now termed "leadership for learning." The document reviews research on defining characteristics and effects of instructional leadership, and how the concept has developed into a paradigm for 21st century school administration.