Guru Amar Das (1479–1574), the third Sikh Guru, was a great social reformer and spiritual leader. He strongly opposed caste discrimination, the practice of Sati, and purdah. He established the system of Manji and Piri for organised religious preaching and promoted the langar (community kitchen) where people of all castes ate together. Through his efforts, he transformed the Sikh community into a well-structured religious society based on equality, devotion, and social justice.