Russia staged its biggest military parade to mark 70 years since victory over Nazi Germany in Second World War.
The parade in Moscow's Red Square featured a re-enactment of historic battles with 16,000 troops and a range of Russia's latest military hardware, according to Radio Free Europe.
Despite Russia's wartime allies, including the US and Britain boycotting the event, more than 20 heads of states were in Moscow to observe Russia's military might.
The most prominent world leaders in attendance were United Nations chief Ban Ki-moon, Chinese leader Xi Jinping, and India's President Pranab Mukherjee.
Egyptian leader Abdel Fattah al-Sisi, Cuban president Raul Castro, Venezuela's Nicolas Maduro, Zimbabwe's Robert Mugabe, and South Africa's Jacob Zuma were also at the parade.
The Red Square parade included a fly-by featuring 150 planes and helicopters:
— Maxim Pushkin (@mc_maxim) May 9, 2015
And lines of Armata tanks:
А вот и танк Армата снова на Красной площади pic.twitter.com/5ilhv891xl
— Дмитрий Смирнов (@dimsmirnov175) May 9, 2015
The parade even featured what has to be the world's first tank selfie:
— Lida Vasilevskaya (@Vasilevskaya_RT) May 9, 2015
Victory Day is a public holiday in Russia, marked by large parades and firework displays in cities across the country.
Russia spent nearly $8m (£5.18m) seeding clouds with silver iodide to prevent rain from spoiling the victory Day celebrations, according to RFE/RL.
The grandiose celebrations reflect the view in Russia that Victory Day was one of the most important events in its history, because the Soviet Union lost an estimated 26 million people in the Second World War: more than any other country.
According to RFERL, the scale of loss during World War II was so severe virtually every Russian family lost a family member.
In his speech, President Putin paid tribute to the sacrifices of Soviet troops during World War Two. He also thanked "the people of Great Britain, France and the United States for their contribution to victory", according to the BBC.
But he added: "In recent decades the basic principles of international co-operation have been ignored ever more frequently. We see how a military bloc mentality is gaining momentum."
The remarks echo previous complaints by Putin about what he says are efforts by the US and its Nato allies to encircle Russia militarily.
US and Western leaders made a show of not attending the event to protest Russia's involvement in the Ukraine crisis.
In response to the snub by the US, a Russian youth group released a video showing World War II-era soviet tanks and modern armoured vehicles, rolling through the Red Square projected onto the White House.
The group blasted president Obama for undermining Russia's Victory Day celebrations.
The video was revealed to be fake, but it highlighted the tension between the Western countries and Russia over the conflict in eastern Ukraine.