The town of Longvek, in Kampong Tralach district, is picturesque but unremarkable. Cows graze between rice paddies and stilted wooden homes dot the landscape. It is hard to imagine that it was once home to a great capital city – surrounded by earthen walls, moats and forest – where merchant ships from as far as Holland and Spain would cast their anchors on the nearby Tonle Sap river.

Even among Khmer people, the six decades in the 16th century during which Longvek was Cambodia’s capital, are remembered as a dark age, culminating in defeat and a “great humiliation” at the hands of Ayutthayan invaders in 1593.

But the finds of an archaeological dig now in its third year suggest that Longvek may deserve a more storied place in Cambodian history.

For the past three dry seasons, a team of Australian, Japanese and Cambodian archaeologists have been unearthing material evidence that points to a flourishing capital city and a crossroads for global trade. Located about 50 kilometres north of Phnom Penh, Longvek’s three sets of walls enclose an area of nearly nine square kilometres.

The city was established as the capital in the 1530s after a period of civil war, in which King Ang Chan emerged victorious over the “usurper” Sdech Khan, but it soon found itself fending off the expanding Siamese Kingdom to the west and Vietnam and Champa to the east.

After the fall of Longvek, Oudong became the seat of the king in the early 1600s before the court eventually moved to Phnom Penh in the mid-19th century.

“A lot of people, especially Cambodians, are not aware of Longvek,” said Phon Kaseka, an archaeologist with the Royal Academy of Cambodia’s Institute of Culture of Fine Arts.

More so than its actual history, the thing most commonly associated with the city are apocryphal tales synonymous with loss. In one, two brothers – Preah Ko, a holy cow, and Preah Keo, a divine human – are captured and taken away by Siamese invaders. The setting of the tale of the brothers’ capture is disputed, but it is most commonly linked to Longvek.

Dr Martin Polkinghorne, an archaeologist from Flinders University leading the dig, said the brothers – who were sacred because Preah Ko held within his body a trove of spiritual knowledge – are likely metaphors for the Buddhist texts, and monks, believed to be taken by the Siamese.

“So this is a story that is constructed to come to terms with this great loss,” he said.

In another story about the sacking of the city, the Ayutthayans, led by King Naresuan, are said to have thrown silver coins into a bamboo forest surrounding the city. In their greed, the Khmer defenders then burnt down the forest to gather up the treasure, leaving Longvek exposed to invasion.

The stories, along with most textual evidence, were written well over a century after the events took place, including in the Royal Chronicles, which for Polkinghorne shows their “unreliability”.

“That’s where archaeology can come in, because we can interrogate the material itself,” he said.

On the grounds of Longvek’s Wat Tralaeng Keng in late January, Polkinghorne pointed out the monument to the two brothers still standing today. The temple is thought to have been established by King Ang Chan himself, and though it was rebuilt several times, it is one of the oldest continually running pagodas in the country.

For Polkinghorne, the evidence above ground, along with what is being unearthed, shows that far from being forgettable, Longvek was very much on the map.

One exceptionally rare find in particular surprised the archaeologists – a set of ceramic fragments of a 16th-century ornamental jar from China’s Fujian province found last month in a trench near a present-day brick factory.

“This is the second discovery [of this ceramic] in the world at an archaeological site,” said Yuni Sato, an archaeology expert from Japan’s Nara National Research Institute for Cultural Properties. The first such find was made at the Sakai temple on the southern coast of Honshu, Japan.

Standing outside a home the archaeological team has rented out in Longvek, Sato picked up a plastic tray with a set of blue and white shards. These she dates to the second quarter of the 16th century and would have made up a ceramic bowl. The presence of such ceramics suggests Longvek was a more significant trading port than previously assumed.

“It’s from the very early stage of Longvek. That the king could import good quality blue and white bowls [means that] this is a piece of evidence of the power of the king of Longvek,” she said.

As the team walked through brush near Wat Sophi Rangsei, where the remnants of an Angkorian-era prasat, or tower, are still visible, the abundance of ceramics on the ground was clear, including fingernail size shards that members of Polkinghorne’s team identified as likely from the Ming dynasty. With each ploughing of the rice fields that dominate the area, he said, an abundance of fragments is brought to the surface to be analysed.

“To import this amount of ceramics, [it means] they had enough power to maintain this size of capital and could trade abroad and already built up friendships with foreign countries,” Sato said, noting that never in her career has she seen such a volume of material at an archaeological site.

Also found last month is an iron blade, raising questions about where such material came from and the state of Cambodia’s military at the time, Polkinghorne said. Several iron nails, he continued, are evidence of complex wooden architecture, though the former site of Ang Chan’s palace, supposedly built in the 1550s, continues to elude the team.

“We’re getting warmer every day,” he says.

While a map made using laser imagery shows the city’s clear foundations, on the ground, the walls appear to be nothing more than mounds of dirt, mundane to the untrained eye, and have at times fallen victim to encroaching development from Phnom Penh.

The threat has not gone unnoticed by the government. Speaking to nearly 100 local commune chiefs at Wat Traleang Keng on January 29, the Ministry of Culture’s Director General of Cultural Heritage Prak Sonnara said legal action would be taken against companies or individuals who violated preservation laws at sites like Longvek, where one case has already caught the ministry’s attention and is ongoing.

“We will have action against those who have committed [the crime]. First, the company which violated the wall, [and] second, we have action against the landlord who sold the land [to the company],” he said. “We don’t ban development, but before you do anything you should ask for legal permission . . . so that we can study the impact first.”

Weighing development versus preservation is a difficult balancing act, Polkinghorne noted, and his team has to tread carefully as they conduct their own work. They are currently using an excavator on a wall segment, which might lead villagers to question why they can’t employ such tools on their own property.

“It’s tricky to explain that such tools can be used delicately,” he says.

But despite the loss of material, already the amount of data collected by archaeologists will keep them busy for the time being, and the ceramics will take years to fully analyse. Thus far, the pottery links Longvek to China, Japan, Vietnam and possibly Europe, Kaseka said.

The Cambridge History of Christianity: Volume 8 notes that Portuguese Dominican missionary Gaspar da Cruz was the first known European arrival to Longvek in 1553, presenting himself at the royal court.

Meanwhile, historical records from the Dutch, Sato notes, indicate the presence of foreign settlements of merchants from Holland, Spain, Portugal, Malaysia, Japan and China along the Tonle Sap river.

While global trade certainly existed before and during Angkor, particularly with India, Polkinghorne said Longvek is marked by “an explosion of trade”.

“This is the beginnings of modern capitalism that is beginning in this age of commerce – a fluorescence of globalisation,” he says.

That idea stands in contrast to the commonly held conception that after the fall of Angkor in 1432, Cambodia entered a “dark age” marked by decline and cultural decay. This may stem more from a lack of information than of cultural output.

“Cambodia in the post-Angkor era was not a dark age or an era of decline, instead we still had our own culture and civilisation that continues from the Angkor era,” the Culture Ministry’s Sonnara said.

While conceptions of loss have “permeated aspects of Khmer culture”, Polkinghorne proposes an interpretation that stems around rebirth instead, beginning with the fall of Angkor.

“This is an idea of political reconfiguration. We can have loss so we can have rebirth and move forward,” he said. Other evidence suggests a prolific culture after the Angkorian era, including 17th-century inscriptions found at Angkor Wat, as well as the writing of the Reamker, a Cambodian interpretation on the Hindu epic the Ramayana.

Aside from what the team of archaeologists has uncovered, it is unclear what intangible culture Longvek may have left behind, such as in customs, cuisine or traditions. For Kaseka, that may be the next chapter of research.

“We hardly identify any traditions that belong to Longvek period at all,” he said.

Additional reporting by Chhay Channyda and Ouk Suntharoth