French President Francois Hollande has given citizenship to 28 Africans who fought for France in World War Two and other conflicts.
Mr Hollande said France owed them "a debt of blood".
The veterans - many from Senegal, and aged between 78 and 90 - received their new certificates of citizenship at the Elysee Palace in Paris.
Campaigners have long been calling for the rights of the veterans, long-term French residents, to be recognised.
"France is proud to welcome you, just as you were proud to carry its flag, the flag of freedom," said President Hollande.
More naturalisation ceremonies are expected to follow for other veterans in France.
One of those granted citizenship on Saturday, Mohamed Toure, said the gesture will go some way towards healing old wounds.
"President Hollande did what none of his predecessors ever imagined. And that repairs a lot of things," he said.
The granddaughter of a Senegalese soldier, Aissatou Seck, who is herself deputy mayor of a Parisian suburb, has been a lead campaigner for African veterans' rights.
Last year, she started a petition that gained tens of thousands of signatures in less than a week.
The veterans have long been struggling for recognition and equality in France.
Until 2010, they received lower pensions than their French counterparts.
Their ambiguous status also meant they lacked access to other benefits and sometimes found it difficult to travel, said the BBC's Africa editor, Mary Harper.
In 1944, dozens of West Africans were shot dead by French troops when they mutinied over unequal pay and pensions.
A few years ago, Mr Hollande acknowledged that French soldiers had gunned down their African counterparts.
But many war veterans are still demanding a full apology.