"When a language nears silence, only rare courage can give it a future. Ol Guru Rohidas Singh Nag (1934–2012) was that courage for the Mundari people. At a time of cultural neglect and linguistic erosion, he envisioned and created the Mundari Bani script, securing a written life for a language long sustained by memory alone. He believed with unshakable conviction that a community survives through its language, and a language survives through its own script. This belief defined his life’s mission. From a humble village background, Rohidas Singh Nag rose to become the guiding force of the Mundari language movement. Revered as Ol Guru, he dedicated himself to protecting linguistic identity and cultural dignity, often in the face of resistance, isolation, and hardship. Through rigorous research and deeply personal narratives, this book reveals the resolve, sacrifice, and moral strength behind his work. More than a script inventor, he emerges as a teacher, cultural reformer, dramatist, and mentor who awakened collective pride and purpose among his people. Written with scholarly depth and emotional power, this biography is not merely the story of one man, but a testament to the enduring strength of indigenous knowledge—and a reminder that the vision of a single individual can change the destiny of an entire community."