Addressing a parade redolent with communist-era imagery, Russian President Vladimir Putin evoked the unity that brought victory but also stressed the Soviet's huge role.
The celebration on Monday brought together leaders of lands that faced off on the battlefields of the war - or across bitter Cold War barriers in the decades that followed.
"I bow low before all veterans of the Great Patriotic war," said Putin, using Russia's name for the second world war. He watched the parade from a podium in front of Lenin's tomb, flanked by US President George Bush, French President Jacques Chirac and German Chancellor Gerhard Schroeder.
Japan's Junichiro Koizumi (R) and
Italy's Silvio Berlusconi attended
War raged in the Soviet Union for years after the Nazi invasion of 1941 before the Red Army began pushing the German forces back. An estimated 27 million Soviets died in the conflict, the largest sacrifice by any one nation.
Putin described 9 May 1945 - marked in Russia as Victory Day - as "a day of victory of good over evil, freedom over tyranny".
Beneath overcast skies, the parade began with four goose-stepping soldiers in ceremonial gold-embroidered uniforms carrying a red flag with a hammer and sickle - a replica of the banner flown from the top of the Reichstag in Berlin after the building was seized by Soviet troops a week before the Nazi surrender.
Far from the elaborate ceremonies in the capital, most Russians observed the day with quiet intensity, following the tradition of making visits to graves of relatives and then dining together.
While Russians often complain that the Soviet's wartime role is underrated in the West, Putin said "we have never divided the victory between ours and theirs, and we will always remember the help of the allies".
"Today we pay tribute to the courage of all Europeans who countered Nazism," he said.
"Today we pay tribute to the courage of all Europeans who countered Nazism"
Russian President Vladimir Putin
He and other leaders laid red carnations and a huge carpet of red roses at the Tomb of the Unknown Soldier to honour soldiers who perished in the second world war before heading inside the Kremlin for a reception.
Along with Western heads of state, Putin's guests included President Hu Jintao of China and Japanese Prime Minister Junichiro Koizumi.
But the celebrations also reopened old wounds created during the war and its aftermath, when the Soviet Union dominated eastern Europe for decades.
At the Kremlin reception, Putin said the victory over Nazis brought "the right to freedom, to life itself, to an independent choice of a path of development" - the kind of remark bitterly disputed in the Baltic states, which were annexed by the Soviet Union and gained independence only with its breakup in 1991.
The leaders of two Baltic nations, Estonia and Lithuania, stayed away, angered by Putin's portrayal of the Soviet Union as a liberator despite decades of occupation.
Bush balanced his Moscow visit with a trip to Latvia, another Baltic nation, and went later on Monday to Georgia, where a new pro-Western leadership is seeking to shed Russian influence.