A ceremony has taken place in central Paris to remember those killed in the Charlie Hebdo attacks a year ago. President Hollande laid a wreath in the Place de la Republique, where a commemorative oak tree was unveiled, and a minute's silence was observed.
In the attacks, jihadist gunmen killed 12 people at the satirical Charlie Hebdo magazine, four hostages at a Jewish supermarket, and a policewoman.
On 11 January 2015, a huge protest against the attacks was held in Paris. Those protests focused on the Place de la Republique. Sunday's ceremony remembered that show of unity, which attracted more than a million participants.
Relatives of some of the victims also attended Sunday's event, the culmination of a week of ceremonies. French rocker Johnny Hallyday sang a song with the French army choir which recalls the 11 January unity march.
France is still under a state of emergency following the 13 November attacks in Paris, in which gunmen linked to the Islamic State group killed 130 people. A plaque unveiled in the Place de la Republique pays tribute to victims of both the Charlie Hebdo and November attacks.
The words of the writer Victor Hugo, on his return from exile in 1870, were also read out, including the observation: "Paris is a sacred city. Whoever attacks Paris attacks the whole of humanity."
President Hollande continued on from the Place de la Republique to the Grand Mosque in Paris. His visit comes as French mosques have been opening their doors to non-Muslims over the weekend to overcome prejudice against Islam.