Tirumandiram (or Thirumandiram) written by the Yoga Siddhar Tirumular (or Thirumoolar) in Tamil, in more than three thousand verses, probably between the 4th and 6th centuries A.D., is the oldest and most important text of Yoga from south India, It is a work of Yoga, tantra, mysticism, mantra, kundalini and monistic theism. The 12th century philosophical school of Saiva Siddhantha traces its origins to it.