[6] Repeated incursions by South Indians, particularly the Cholas, into Sri Lankan territory occurred throughout the next few centuries and led to the engagement of the rival forces in battle.

[7] In one famous encounter, Sinhalese King Dutugamunu (161–37 BC) raised an army of eleven thousand in his battle against the Chola invader Elara, whom he eventually defeated.

[8] Other Sri Lankan monarchs whose military achievements stand out include Gajabahu I (113–35), who sailed to India to bring back his captured soldiers, and Dhatusena (455–73) who is credited with repulsing numerous Indian invasions and for organising a naval build-up to deter seaborne attacks.

His reign included a military expedition to Burma in retaliation for indignities inflicted on his envoys and Burmese interference in the elephant trade.

Another strong ruler in the Transitional period of Sri Lanka was Parakramabahu VI, who defeated Indian invaders, united the island and ruled it from capital Kotte.

[8] Although the known epigraphical records do not indicate that the Sri Lankan rulers had a full-time standing army at their disposal, there is evidence supported by legend, designation, name, place and tradition that prove there were 'stand-by' equestrian, elephant, and infantry divisions to ensure royal authority at all times.

Militias were raised as the necessity arose, and the soldiers returned to their pursuits, mainly for farming, after their spell of military duty.

Yet, until the entire island was ceded to the British in 1815, regional kingdoms maintained most of their independent defence forces and were able to successfully repulse repeated thrusts by the European armies.

In 1505 a Portuguese fleet, while operating in the Indian seas against Arab traders, was blown off course and landed at Galle, on the southern coast of the island.

Thus the Portuguese were forced to restrict their presence in the island due to their small numbers and their efforts were more focused toward projecting maritime power.

The Dutch Forts in Jaffna, Galle, Matara, Batticaloa and Trincomalee were sturdily built and are considered a tribute to their military engineering skills.

[8] Initially the British stationed their forces, which included naval vessels, artillery troops and infantry, to defend the island nation from other foreign powers, using the natural harbor of Trincomalee as their headquarters in Sri Lanka.

During the first half-century of occupation, the British faced a number of uprisings, and were forced to maintain a sizable army in order to guarantee their control over the island.

During the First World War, many volunteers from the Defence Force travelled to Great Britain and joined the British Army, and many of them were killed in action.

One of them mentioned by Sir Arthur Conan Doyle was Private Jacotine of the CLI, who was the last man left alive in his unit at the Battle of Lys,[10] and who continued to fight for 20 minutes before he was killed.

In 1948 Sri Lanka gained independence from Britain, becoming a Dominion within the Commonwealth and a year earlier Ceylon entered into the bi-lateral Anglo-Ceylonese Defence Agreement of 1947.

The initial requirement was to raise an artillery regiment, an engineer squadron, an infantry battalion, a medical unit, and a service corps company.

Thereafter the government mistrusted the military and reduced the size and growth of the army, especially the volunteer force, disbanding several units and forming the Gemunu Watch.

This was later seen as a tactical error, as the Indian Peace Keeping Force united nationalist elements such as the JVP to politically support the LTTE in their call to evict the IPKF.

New weapons and equipment were introduced as the war shifted from counter-insurgency to conventional warfare tactics, with multi battalion, brigade and division scale operations.

However, renewed violence broke out in December 2005 and following the collapse of peace talks, the Army has been involved in the heavy fighting that has resumed in the north and east of the country.

On 19 May 2009 Sri Lankan army declare the victory of war as they found the dead body of LTTE leader Velupillai Prabhakaran.

[19][20] A panel of experts appointed by UN Secretary-General Ban Ki-moon to advise him on the issue of accountability with regard to any alleged violations of international human rights and humanitarian law during the final stages of the civil war found "credible allegations" which, if proven, indicated that war crimes and crimes against humanity were committed by the Sri Lankan Armed Forces and the Tamil Tigers.

[33][32][34][35] In January 2019, a Sri Lankan army officer and trooper on peace keeping duty in Mali were killed and three more wounded when their convoy came under an IED attack.

[62] In 2021, a special 'Women Corps Quick Reaction Rider Team' was formed to operate in an emergency situation in Jaffna; female soldiers were in motorcycles.

New sources of weaponry in the mid-to-late 1970s included the Soviet Union, Yugoslavia, and China – countries with which the leftist Bandaranaike government had close ties.

These APCs enabled the Armoured Corps to have their own assault troops to provide close contact protection to their Alvis Saladin and Ferret Scout Cars which were vulnerable to anti-tank weapons.

These land mines weighed approximately 50–100 kg, against which no armoured vehicle that the SLA possessed was able to withstand the blast effect.

Recently the Sri Lankan Army started to produce locally weapons such as a new multiple rocket launcher, with 10 barrels and a firing range of 20 km.

[68][74] Inaugurated on 12 July 1984,[85] Sri Lanka Army Seva Vanitha Unit[86] functions with the main objective of providing welfare facilities to the next of kin of war heroes who have sacrificed their lives, gone missing in action or injured whilst defending the sovereignty and territorial integrity of their motherland while also empowering the families of the serving Army personnel.