Fort Fredrick , also known as Trincomalee Fort or Fort of Triquillimale, is a fort built by the Portuguese at Trincomalee, Eastern Province, Sri Lanka, completed in 1624 CE, built on Swami Rock-Konamamalai from the debris of the world famous ancient Hindu Koneswaram temple (Temple of a Thousand Pillars). The temple was destroyed by the Portuguese colonial Constantino de Sá de Noronha under Phillip III, occupier of the Jaffna kingdom and Malabar country on the island. On the Konamalai cape was also built a new village of Portuguese and Tamil people, 50 Portuguese soldiers and inside the fort, a church named after "Nossa Senhora de Guadalupe". The Fort of Triquillimale was dismantled and rebuilt by the Dutch in 1665, renamed Fort Fredrick.

Several Hindu shrines in the Tamil country were destroyed during the occupation, particularly under Philip II, when Trincomalee became the scene of naval battles during Europe's Thirty Years' War. King Ethirimana Cinkam of the Jaffna kingdom had resisted a call by D. Jerónimo de Azevedo in 1612 to aid the latter in building a fortress in Trincomalee. The enterprise was abandoned.With the defeat of King Cankili II, all of the territory of the kingdom of Jaffna, comprising Trincomalee and Batticaloa, was assigned to the "spiritual cures of the Franciscans." This decision was taken by the bishop of Cochin, fray Dom Sebastião de S. Pedro. By the end of 1619, a small Danish fleet had arrived at Trincomalee; in May 1620, the Danes occupied Koneswaram temple and began works for the fortification of the peninsula before being defeated.

The shrine was attacked and destroyed on April 14, 1622 CE, the Tamil New Years Day, by the Portuguese general Constantino de Sá de Noronha (who called it the Temple of a Thousand Pillars). The main statue was taken out to town during the 'ther' (chariot or car) procession, during which time Portuguese soldiers entered the temple dressed as Iyer priests and began robbing it. In an act of religious zeal, the temple was then levered over the edge into the sea. Fleeing priests buried some of the temple's statues in the surrounding area. Temple stones and its carved pillars were used to construct Fort Fredrick to strengthen the colonists' influence over the eastern seaboard of the island against other invading European armies, including the Dutch navy during the Dutch–Portuguese Wars. An extensive campaign of destruction of five hundred Hindu shrines, the Saraswathi Mahal Library and forced conversion in the Tamil country was conducted by the Portuguese upon their arrival to the island and conquest of the Jaffna kingdom; the temple had been paying protection fees of 1280 fanams a year to the Portuguese. Trincomalee witnessed several naval battles of Europe's Thirty Years' War under Phillip II's man Filipe de Oliveira. Between 1639–1689 CE, the Ati Konanayakar temple was built in nearby Thampalakamam to house the idols on procession that survived. The destruction of the Konesar temple is historically viewed as the biggest loot of one of the richest temples of Asia. Gold, pearls, precious stones and silks collected for more than 1000 years were robbed within a few hours. A site plan by De Queiroz states: "On the first rise to the summit of the rock was a Pagoda, another at mid-ascent, and the principal one of them all at the highest eminence, visited by a concourse of Hindus from the whole of India." In his dispatch to Philip III, King of Portugal, Constantino described: "The land of the Pagoda is 600 fathoms long and 80 feet at its broadest, narrowing to 30 feet." The final monument of the temple complex was destroyed two years later. Regarding a prophetic Tamil inscription de Noronha found at the site, he added "When I went there to make this Fort, I found engraved on the Pagoda, among many other inscriptions, one that ran thus: Kulakottan has built this pagoda..."