VILNIUS, Lithuania — Under French tricolor flags, the remains of 3,000 French soldiers who froze or starved to death two centuries ago during Napoleon's catastrophic invasion of Russia were laid to rest Sunday in Lithuania.

Guns from an honor guard echoed through the pine trees during the burial of the remains, discovered two years ago in a nearby mass grave seen at the time as a major archaeological find.

Lithuanian leaders, French diplomats and other representatives of this former Soviet republic's diplomatic corps were among 300 people at the ceremony at the Atakalnis Cemetery, in the heart of the capital Vilnius. The hilltop graveyard usually is reserved for Lithuanian independence heroes, writers and leading politicians.

France's ambassador to Lithuania, Jean Bernard Harth, said the day was a time to reflect on European peace and unity.

Priests blessed a granite, wall-like monument to the soldiers, among the last remnants of a French force that had numbered over 500,000 men.

Also at the service were at least 50 French men and women who belong to clubs and societies celebrating the life of Napoleon, who once ruled over most of continental Europe.

Since Napoleon's soldiers came from all over his empire — including Italy, Germany, Poland and Lithuania — there was never a question of returning the remains to France, officials said.

"I'm very happy those men in that 20-nation army have finally found a resting place in Lithuanian soil," said Bernard Brusseau, a descendant of a French soldier who died during the Russian campaign.

In more festive commemorations the day before, 1,000 men in period costumes re-enacted battles of the ill-fated French attack on the Russian Empire in 1812. Russian Cossacks and French hussars crossed swords and dashed with horses through thick cannon smoke.

Afterward, the mock combatants shook hands and hugged — a symbolic though far from historically accurate reconciliation.

Napoleon's army that marched into Lithuania bound for Moscow was one of the largest forces ever assembled. Six months later, the remaining 40,000 men retreated to Vilnius in bitter winter weather.

Cold and starving, some of the soldiers are said to have raided medical schools to eat preserved human organs. Others reportedly gnawed on leather belts. Most quickly died, their frozen corpses filling the city's cobblestone streets and squares.

Reoccupying Russians spent months removing the dead. They couldn't dig graves in the frozen-solid ground, so they burned many bodies.

As the smoke and stench became unbearable, the Russians threw the bodies into a V-shaped defensive trench dug months earlier by French. It was the trench, forgotten for centuries, that Lithuanian bulldozers accidentally unearthed at a housing development in 2001.

At first, many thought the remains were dissidents executed by secret police during Soviet rule, which ended in 1991. The area had been a major Red Army base.

Coins with Napoleon's image and buttons of his Grand Army found amid the remains helped researchers identify them as remnants of the French force, said Arunas Barkus, of Vilnius University.

Many of the skeletons were found curled fetal positions and undamaged, suggesting they died of exposure not in fighting, according to Barkus.

Napoleon said the weather, not poor planning, was to blame for his defeat — one that marked the beginning of the end of his rule. His downfall was sealed at Waterloo, Belgium, in 1815.

Archeologists said there should be at least 20,000 other skeletons of French troops buried in and around Vilnius and they intend to keep searching for them.