India’s journey from the Naxalbari uprising of 1967 to becoming Naxal-free in 2026 represents one of the most remarkable achievements in the history of its internal security. This chapter provides a comprehensive understanding of Left-Wing Extremism (LWE) by examining its ideological foundations, historical evolution, causes, impact on national security, and the transformation of India’s counter-insurgency strategy. It explains how an integrated approach based on security, development, rehabilitation, and good governance successfully weakened Maoist influence while restoring peace and democratic governance in conflict-affected regions. Through detailed analysis, case studies, timelines, and practical insights, the chapter highlights the lessons India’s experience offers for addressing contemporary and future internal security challenges.