Complex sentence: Dravidian martial arts have been practiced in South India and northeastern Sri Lanka since at least the 2nd century BCE, when forms of martial arts were mentioned in Sangam literature at the time.
Split into simpler sentences: Dravidian martial arts have been practiced in South India and northeastern Sri Lanka since the Sangam period. The origins of martial arts in ancient Tamilakkam date back to the 2nd century BCE, when various martial arts were described in Sangam literature at the time.