Langar was a concept introduced by Guru Nanak Dev, first Guru of Sikh religion who is the founder of Sikhi (Sikhism), during the 1500s. It was designed to uphold the principle of equality between all people regardless of religion, caste, color, creed, age, gender or social status. This was a revolutionary concept in the caste-ordered society of 15th century India, where Sikhism began. In addition to the ideals of equality, the tradition of langar expresses the ethics of sharing, community, inclusiveness and oneness of all humankind.