Bhai Dooj is a Hindu festival where sisters apply tilak, feed brothers and pray for their long life, rooted in legends of Yama and Yamuna and Krishna. Celebrated across India, Nepal and beyond with regional customs, including Yamuna bathing at Mathura, Godhan Puja, Bhai Phonta and Bhau Beej, its rituals affirm sibling bonds, protection and cultural continuity.