Over the past week, all over the country, Chinese-Cambodian families bearing food, decorative paper, incense and other offerings have been making pilgrimages back to their hometowns for the Ching Ming Festival – one of the year’s most important holidays for the Chinese-Cambodian community and a testament to the deep cultural influences that have migrated south.

Today is the last day of celebrations during the 2,500-year-old “tomb-sweeping” holiday – so called because families clean and adorn their ancestors’ graves during the festival, which officially lasts three days but often is celebrated for as long as a week.

For the Sok family, this week’s festival means a trip from the capital to Pursat. This is the first time in seven years that the eldest son, Rathanak, will take part in Ching Ming.

Though he has been back to his family home in Pursat town for other occasions, he has not been to the plot of land in the countryside near where his great-grandfather first settled in Cambodia and where his ancestors are buried. “I feel [it’s been] so long [since] I’ve been there and I just feel like I should meet my ancestors,” he says. “I’m afraid they don’t know me anymore.”

The family of seven pile into a car to make the six-hour drive from Phnom Penh back to Pursat province. Early the next morning, Rathanak and his relatives get up to cook the offerings before driving for another half hour to a plot of land in the countryside where they remove the weeds from the large burial mound and decorate it with coloured paper.

Rathanak’s mother, Kan Saroeun, explains that this symbolises cleaning out the ancestors’ homes and building them shelter.

Five sets of rice, tea and wine, along with a whole roast pig, two boiled chickens, a selection of canned drinks, several platters of fruits and other packaged food are laid out in front of the burial mound. The family members take turns kneeling and offering prayers, after which they begin burning paper offerings.

Each has a very literal purpose – paper clothes for cover, a large villa for shelter, passports and visas for travel, and a whole range of fake bills – in different currencies to save the ancestors the hassle of exchanging money. These material comforts are offered to their ancestors in the hopes that they will bless them similarly in return.

After the ceremony, the family divvies up the food they brought for worship as a sign of good luck and to signify family reunion with their ancestors. The legs of the roast pig are removed and served to the men in the family. “Men can work and earn more money than women . . . This is so [the men] can run fast,” Sok Chhan says, using a figure of speech meaning to go far in life.

Though the festival dates back several millennia, its current form was enshrined during the Tang dynasty approximately 1,300 years ago. To curb the practice of wealthy Chinese holding frequent and elaborate ceremonies to honour their ancestors, the Emperor Xuanzong restricted such offerings to once per year – over Ching Ming.

The Sok family has never missed holding the ceremony, even when doing so could have threatened their lives. During the Khmer Rouge regime all forms of religious worship were banned and, like other groups who were seen as not being fully Khmer, Chinese-Cambodians were treated brutally. Of the nearly half a million Cambodians of Chinese descent before 1975, historians estimate half were killed.

According to Saroeun, in Democratic Kampuchea the family could not make any offerings, but continued to pray quietly at home. “When Vietnam invaded Cambodia, we also celebrated [the holiday], but it depended on our living conditions,” she said.

“We did what we could afford.”

Such is still the case for many families. The offerings each make differ widely depending on the wealth and size of the family.

As the Sok family sits down to eat and drink at the cemetery in Pursat, another branch of their family arrives to pay respects to their ancestors at a neighbouring mound.

Similarly, they decorate the graves and lay out their offerings, which are considerably humbler in comparison – rice, bowls of fried vermicelli, a small bag of fruits, one chicken, and a hunk of pork in place of a whole pig.

While they also have paper offerings, noticeably absent is the visually striking large paper villa. One young woman, Chouob Chan, says that the family comes to the cemetery to honour their ancestors even though they do not have money to buy that many offerings. “We do what we can, and it is better than nothing,” she says.

Additional reporting by Rinith Taing