According to LTTE leader Velupillai Prabhakaran, the Sri Lanka Armed Forces feared the Jeyanthan Brigade the most and sought to avoid direct clashes with them.

The regiment was named after the LTTE's first Eastern Sea Black Tiger, Captain Jeyanthan, who destroyed a Sri Lankan Naval Patrol Vessel off the coast of Point Pedro on 4 May 1991.

During Operation Jayasikurui, the Sri Lankan Army concentrated 5 fighting Divisions(50,000 soldiers) for a major offensive to invade the Vanni and smash the LTTE heartland.

Despite suffering over 150 casualties in a bloody assault on the Vanunathivu military base in Batticaloa, the Jeyanthan brigade still relocated the bulk of their forces towards the Vanni front on Prabhakaran's command and played an instrumental role in halting the SLA advance at Puliyankulam.

However, most commanders of the brigade, including Col. Keerththi, Col. Nagesh, Col. Ram, Lt.Col Jeyaaththan and Lt.Col Bhavaan, all remained loyal to Prabhakaran and helped the LTTE leader's hand in crushing Karuna's Rebellion during the Easter offensive of 2004.