Koneswaram temple at Trikonamalai (Trincomalee), Sri Lanka is one of the very ancient temples in this region. But it has a very sad history behind it. Why ? Read on
Like many ancient temples, Koneswaram was also renovated / rebuilt by many kings. It was a descendant of Manu Neethi Chola, Kulakottan who extensively renovated the temple around 5th century. Saint Sambandar sings about the sthalam during 6th century :
குரைகடல் ஓதம் நித்திலங் கொழிக்குங் கோணமா மலையமர்ந் தாரே

Subsequently Pallavas and Cholas did lot of renovations to the temple. There is an inscription of Rajaraja Chola in the temple. Pandyas also made lots of grants to the temple & there is Pandya insignia, Irattai Kayal, in the temple. Jatavarman Sundara Pandyan gold plated the Vimana like he did in the temples of Tamilagam. The temple complex was a huge one and housed three shrines. But all changed when the European powers landed here

Portuguese captured the town during early 17th century and was trying to demolish the temple. The citizens of the town resisted it and even started paying a Temple protection tax to Portuguese to save the temple. During 1622, a Portuguese general Constantino de Sá de Noronha came to this place and he wanted to built a fort in the place where the temple stood.

On the sacred day of Tamil New Year, April 14th 1622, the temple was in festive mood. Many Portuguese soldiers went inside the temple disguised as priests and started looting the temple treasures.
The Portuguese army started attacking the temple but they were struggling to demolish it as it was a strong structure. Heavy guns were used both in land & sea for days to bring down the temple completely. During that time, priests took many of the Vigrahas to safety & buried them. Major parts of the temple was immersed in sea. Whoever tried to resist were killed mercilessly.
A fort was built from the ruins of the completely destroyed temple

Few years later, a small temple called as Adi Koneswaram temple, was built by the devotees in a nearby place with whatever idols saved. Centuries later, during 1950, while digging a water well, the Vigrahas of Somaskanthar, Mathumai Amman, Vinayagar and a number of other Vigrahas were recovered.
During 1956, Arthur C Clarke discovered the ruins of the ancient temple during scuba diving. Inscriptions in Pallava Grantha was found and to top it all, the swayambu Lingam of the temple was found among the ruins. All of them were installed in the present temple.

Today, the temple is a small replica of the giant temple complex which stood here for thousands of years only to be demolished by invaders. It is still waiting for the old glory to be restored.