Video report from ITV News' James Mates
French president Francois Hollande today vowed to destroy "the army of fanatics" responsible for the Paris attacks as he led a memorial service to the 130 victims.
In a poignant but defiant speech, Mr Hollande urged his country to continue to go to restaurants, bars and sporting events and to enjoy the simple pleasures he said Islamic State hated.
The names and ages of the 130 victims including Nick Alexander, from the UK, were read out during the service at the military museum Les Invalides.
The majority of the victims were under 35 with the youngest being 17 and the oldest 68. They came from 18 countries including France.
Hollande said the attacks were part of a chain stretching back to the September 11, 2001 attacks in the US, and he noted that many other countries - including, this month alone, Mali and Tunisia - had been hit by militant groups.
"We will defeat this enemy. Together. With our forces, those of the republic. With our arms, those of democracy. With our institutions, with international law," he added.
A military orchestra was then accompanied by a choir who gave a rousing rendition of La Marseillaise.
Some victims who were wounded in the attacks were among those gathered for the service along with friends and relatives of those killed.
Survivor Charlotte Brehaut, who attended today's service, was in one of the restaurants that was targeted during the attacks.
She said the French president delivered a "very powerful message" with his speech and that the mood at the service was "very sombre."
Former French president Nicolas Sarkozy and French National Front leader Marine Le Pen were among political figures who gathered for the service.
However, a handful of the victims' families boycotted the ceremony, saying the government failed to take sufficient measures to protect the nation in the wake of the jihadist shootings at Charlie Hebdo satirical newspaper and a Jewish supermarket in Paris in January.
"Thanks Mr President, politicians, but we don't want your handshake or your tribute, and we hold you partly responsible for what has happened!" Emmanuelle Prevost, whose brother was one of the 90 slaughtered at the Bataclan concert hall on November 13, wrote on Facebook.