Sootha is the name of a race i.e. social order in ancient Indian society . People born out of a converse marriage between a Kshathriya man and Braahmana woman were called Soothas . They were allowed to adopt the vedic and social culture as for the kshathriyas .Their status was below that of Kshathriyas and above that of Vyshyas , i.e. between 2 nd and 3 rd orders . Yet, they had marital relations with kings . The race once had a province of their own too , called Sootha land.
The principal profession of the soothas was to build and drive chariots . The word "sootha" is a synonym for a chariot-driver. Sootha, Yanthaa, Saarathi and Kshaththa (also spelt as kshaththri) are all the names of a chariot-driver or driver in general. But, Santhi parva , verse 12-39-43 mentions soothas among bards. Maybe some soothas were professional bards too.
In the Mahaabhaaratham, the prominent people who belonged to sootha community were : Adhiratha, Karna , Keechaka and Sanjaya .
Adhiratha was one belonging to the Sootha community. He was one of the Sootha chiefs in Dhritharaashtra's retinue. Once, he stumbled upon a basket floating in the river and found a boy in that basket. He took him home to give to his wife Raadha and brought him up as his son. The boy was none other than Karna himself who was born to Kunthi from sun god when she was unmarried. She put the baby in a basket and left it in the river. It was that basket that Adhiratha found . As only five or six people knew that Karna was not really a Sootha, almost all people referred to him as a Sootha or a Sootha's son or Raadheya, meaning Raadha's son. On many occasions, Bheema, Arjuna, Ashvaththaama and Shalya jeered at Karna ridiculing him about his caste. In turn, Karna too mocked at Drona and others pointing out their Braahmana caste. It was not uncommon those days to chide others by naming their caste.