Alvars were the South Indian poet-saints who worshiped Vishnu while the Nayanars were the saints devoted to Shiva. Nizamuddin Auliya, also remembered as Hazrat Nizamuddin was a sufi saint under the Chisti (Sunni Sufi) order. Namghar literally meaning the house of prayer were places of congregational worship introduced by Shankaradeva, a Vaishnav saint in Assam.Gautam Buddha questioned social differences in the society and espoused social justice.