All over France, blue-white-red national flags flew from buildings on Friday.
President Francois Hollande asked the people to hoist the tricolor in patriotic solidarity with the 130 people terrorists massacred two weeks ago in Paris.
And in a grand square, Hollande called people together to mourn the killings in a national ceremony.
Attack survivors appeared as guests of honor alongside grieving families of those killed and diplomats representing countries of victims hailing from outside France.
Since the November 13 attacks, France has been at war with the militant group, Hollande has held, and he has vowed to destroy it.
On Monday, French war planes flew airstrikes against ISIS from the aircraft carrier Charles de Gaulle.
