Having undergone Battalion Training, on 31st March 2002 the troops arrived at Welioya and remained there for a few months. Later, on 5th July 2002 troops moved on to Jaffna again by sea via Trincomalee and were stationed at Eluthumaduwal. On 11th March 2003, an Officiating Commanding Officer took over duties from the outgoing Commanding Officer Major AMR Darmasiri.
26th December 2004 was a tragic day for all of Sri Lanka. What is now referred to as the Asian Tsunami hit many coastal areas killing over 50,000 people with many more made to disappear without a trace. The destruction of property amounted to several billions worth. Without doubt this was the most serious calamity the country had experienced. The Sri Lanka Army stepped into assisting the affected as well as engaged in work directed at restoring normalcy to the affected areas.
Though no one was hurt in the Porathivu area where the 'C' Company of the Battalion was stationed, it was hit by the tidal waves (Tsunami). In the immediate aftermath while searching the area the troops recovered the body of a soldier belonging to the 9th Battalion Sri Lanka Light Infantry and a few people who had received injuries. It was also found that a large number of homes had been destroyed thus rendering the occupants homeless. These affected people were provided with aid and assistance extended by the troops deployed the area.
The 'C' Company was temporarily relocated from Porathivu to Nagarkovil but, returned to Potipathivu after a short period. On 31st of July 2002, the Battalion was redeployed in 'Elukkumadduval' in Jaffna after serving in Welioya. Lieutenant Colonel KAWP Kumarapperuma appointed as the Commanding Officer of the Battalion on 12th March 2003. On 26th December 2004, the 1st Battalion Sri Lanka Sinha Regiment involved itself in the task of providing relief to those who were affected by the Tsunami. Lieutenant Colonel AP Pallawela RWP RSP was appointed as the Commanding Officer of the Battalion on 19th December 2005. On 8th January 2006 Lieutenant Colonel HMP de Silva took over as the Commanding Officer.
Initially, the Battalion supported the Humanitarian Operation while being deployed at Kilali, Jaffna. Security of the Muhamale entry/exit point was ensured by the 1st Battalion of SLSR attached to the 53 Division. In early 2007 the battalion succeeded in hindering enemy activity by way of effective reconnaissance using small boats in the Colombaturai Lagoon and the areas bordering the lagoon. On completion of duties in Jaffna the Battalion now commanded by lieutenant Colonel KRKKT Bandara was attached to the 23 Division in the mid of 2007 as part of the troops engaged in the 'Humanitarian Operation'and was successful in destroying many points of the enemy while recovering a large number of their weapons.
In the beginning of 2008, the Battalion was attached to the 59 Division to be engaged in the Humanitarian Operation in the Wanni region. The Operation itself was launched from Janakapura in Welioya and extended to Mullaitivu via Nayaru and Alampil. The Battalion contributed immensely towards the success of the operation.
