Long considered a day of mourning by New Caledonia's indigenous population, 24 September is infamous on the Pacific Ocean islands as the date France claimed them in 1853. With unrest flaring once again over the question of self-determination, this year's anniversary is expected to be especially tense.
Thousands of police officers will be deployed across New Caledonia this Tuesday, which marks 171 years since French forces annexed the archipelago.
The date remains loaded in a territory divided between loyalists who want to stay part of France and indigenous Kanaks – and others – who argue for independence.
Attempts to turn the anniversary into a celebration of unity haven't neutralised its charge and this year, amid some of the worst rioting in decades, authorities fear recalling colonial violence will galvanise protesters further.
Colonial project
While European explorers, traders, missionaries and slavers had been interested in the islands they christened New Caledonia since the late 18th century, France was the first power to stake a claim.
Emperor Napoleon III saw the opportunity to establish a foothold in the Pacific, where Britain had already extended its empire, as well as answering French missionaries' pleas for protection from hostile locals.
On his orders, Admiral Auguste Febvrier-Despointes landed at Balade, site of a Catholic mission on the northern tip of the main island, and had his men hoist the French flag.
The annexation order he issued on 24 September 1853 was signed by French officers and missionaries, but not a single local representative.
Painful legacy
A ruthless campaign followed to establish control over the rest of the territory, the start of decades of dispossession and displacement for local populations.
A decade later, France turned New Caledonia into a penal colony – allowing it to exile inconvenient prisoners while settling the islands with tens of thousands of white Europeans.
French authorities turned over confiscated land to colonial officials and freed prisoners, while indigenous inhabitants were ultimately relegated to reservations.
Historian Isabelle Merle, who specialises in colonisation in the Pacific, calls it "a unique colonial history".
"The strategy of the state from 1853 was to deliberately introduce wave upon wave of French migrants to populate the territory," she told RFI.
"They tried to transform it into a 'little Austral France' as they called it in the 19th century."
From mourning to reconciliation
New Caledonia remained a French colony until 1946, when it instead became an overseas territory of France.
The change in status paved the way for full citizenship and voting rights for Kanak people, who by then had seen their numbers severely reduced.
As a drive for independence gathered pace in the 1970s, the movement declared 24 September a day of mourning.
But after years of violence throughout the 1980s, then political accords that laid down a roadmap for the territory to govern itself, the early 2000s saw a new appetite for reconciliation.
Key dates in New Caledonia’s history
In 2003, for the 150th anniversary of the annexation, New Caledonia's pro-independence Culture Minister Déwé Gorodey led a push to reclaim 24 September as a "festival of citizenship".
New Caledonians of all backgrounds were invited to gather around the Mwa Kaa, a monumental totem pole erected in the capital, Nouméa, in a spirit of unity.
A plaque at its base bears an extract from the 1998 accord that set a timeline for autonomy: "The past was a time of colonisation. The present is a time of sharing, through the achievement of a new balance. The future must be the time of an identity in a common destiny."
Tensions high
New Caledonia has officially marked 24 September as a celebration of unity since 2004, but the anniversary remains a powerful symbol of French oppression for pro-independence campaigners.
This year, an association of customary chiefs plans to hold a ceremony unilaterally declaring sovereignty over their traditional lands.
It comes amid unrest over a proposed constitutional reform on voting rights that Kanaks believe would weaken their bloc and make independence harder to achieve in any future referendum.
At least 13 people have died in clashes since May – most recently two men shot and killed by police in the pro-independence stronghold of Saint Louis last week.
Deadly unrest in New Caledonia tied to old colonial wounds
Authorities have cautioned against public gatherings on Tuesday's anniversary, citing calls on social media for fresh demonstrations.
Some 6,000 police and gendarmes have been mobilised, while a curfew is in place from 6pm to 5am.
"It's a celebration that should bring people together around the ideas of shared destiny and citizenship, certainly not divide them," Théophile de Lassus, chief of staff for the French high commissioner in New Caledonia, told the local branch of FranceInfo.
"And if some people want to divide and attack New Caledonians, the State will respond very firmly."
