Up to 200,000 Harkis -- the name comes the Arabic word for "movement" given to the mobile units in which they served -- fought for the French colonial power during the 1954-62 war with Algeria's National Liberation Front (FLN).

After a peace accord granting Algerian independence was signed on March 18, 1962, only around 42,000 Harkis were allowed to go to France, some bringing their wives and children.

The French government initially refused to recognise their right to stay and many were held for years in squalid internment camps.

In all up to 90,000 men, women and children fled. The rest remained in Algeria, where many were massacred.

Harki activists in France who tried to prosecute Algeria in 2001 for crimes against humanity claimed 150,000 were killed.

- Fight for recognition -

Despised as traitors in Algeria, in France the Harkis were an inconvenient reminder of a painful defeat.

The seven-year war of independence in Algeria saw nationalists rise up against and eventually defeat their French colonial rulers. There were atrocities on both sides and the conflict left some half a million dead.

Some 400,000 Harkis and their descendants live in France today.

They have fought a decades-long struggle, including hunger strikes and demonstrations, for official recognition of what happened to those left behind in Algeria.

Their integration into France has been difficult as they are considered immigrants but are rejected by other immigrants.

Former Algerian president Abdelaziz Bouteflika compared them with Nazi collaborators during a visit to Paris in 2000.

While criticising the conditions under which they were housed in France, he ruled out their return to Algeria.

- 'Inhuman conditions' -

In September 2001, France held its first ever national day to honour to the Harkis.

Right-wing politicians have rallied to their cause -- often during election campaigns -- but with little concrete results.

In September 2016, Socialist president Francois Hollande formally admitted that France "abandoned" the Harkis.

"I recognise the responsibility of French governments in abandoning the Harkis, the massacres of those who remained in Algeria and the inhuman conditions for those transferred to camps in France," Hollande said.

Two years later a 40-million-euro aid package was created for them and their families.

The same year, France's highest court ordered the state to pay compensation to the son of a Harki for damage to his health in the camps.