Early career Wimalaratne joined the Ceylon Army as an
Officer Cadet in August 1962 and underwent training at the
Indian Military Academy, in
Dehradun as part of the first batch of four Ceylonese cadets sent to Dehradun. There he was the first foreign cadet to be appointed
Battalion Cadet Adjutant in his final term. On his return, he was commissioned as a
second lieutenant in the newly formed
Gemunu Watch on 1 August 1963, leaving soon after for a jungle warfare course in
Malaysia at the
British Army Jungle Warfare Training School. In 1970, he was appointed as an
instructor conducting the
jungle warfare phase for Officer Cadets at the
Army Training Center (ATC) in
Diyatalawa. He served till 1979 becoming the Chief Instructor of the Army Training Center, having introduced training on
urban warfare and
counter-insurgency. The 1st Gajaba Battalion was deployed to the Jaffna peninsula between 1983 and 1984 and again in 1985 with the escalation of the
Sri Lankan Civil War. In addition, during this time Wimalaratne served as Acting Commander, North Central Command and Deputy Commander (Operations),
Security Forces Jaffna. In 1985, he help initiate the
Army Special Forces program having established the first Special Forces Squadrons.
Operation Liberation Operation Liberation (commonly known as the Vadamarachchi Operation) was launched after months of planning on 26 May 1987.
Colonel Wimalaratne was one of the field commanders of the operation, serving as the
Brigade Commander of the 1st Brigade which consisted of the
1st Gemunu Watch and
1st Gajaba Battalion. The
brigade group consisting of the 1st Brigade and 3rd Brigade, commanded by Brigadier
Denzil Kobbekaduwa it was the largest formation deployed by the Sri Lankan Army at that point and the first
conventional battle to take place in the civil war. The objective was to take the territory of
Vadamarachchi in the
Jaffna Peninsula from
LTTE (Tamil Tiger) control. 1st Brigade broke-out of Thondamanaru area with the infantry wading across the lagoon, but was stopped by a mine-field. With the
combat engineers clearing a path across, 1st Gajaba Battalion broke-out and reaching the coast, troops from the 1st Brigade defeating the defensive line commanded by the LTTE leader
Soosai, made a 90 degree turn undertaking a pincer movement capturing Valvettithurai. By 31 May, the government declared that the Vadamarachchi region recaptured. During the operation Kobbekaduwa and Wimalaratne were nearly killed when the house closed to them exploded due to a bobby-trap.
JVP Insurrection With the second phase of Operation Liberation being abandoned with the Indian intervention by
Operation Poomalai and the arrival of the
Indian Peace Keeping Force (IPKF), the
1987–1989 JVP insurrection began in the south of the country. Colonel Wimalaratne was appointed Commander, Garrison Command - Colombo; in charge of defense of the capital in late 1987. In 1988, he received concurrent appointment as the Principal Staff Officer,
Joint Operations Command (JOC) and serving as its Director Operations. He held both posts until the insurrection was subdued in late 1989 with the capture of the leader of the JVP. In January 1991, Brigadier Wimalaratne succeeded Brigadier Jaliya Nanmuni as
Brigade Commander,
21 "Jaffna" Brigade. ==Death==