To the booming chords of the Russian national anthem, president Vladimir Putin stood with his features set in grim determination, as the plan he had set in motion just two weeks ago was completed.
Standing stark upright in front of the Duma as the anthem played, Putin signed bills completing Russia's annexation of Crimea, and hailed the annexation as a "remarkable event".
It follows last weekend's referendum, in which residents of the Black Sea peninsula overwhelmingly backed a breakaway from Ukraine.
President Vladimir Putin has signed bills completing Russia's annexation of Crimea
Ukraine's interim president warned on Friday that he did not want to "start World War Three" with Russia, ruling out military action.
EU leaders have now signed an agreement with Ukraine which aligns the new administration in Kiev more firmly with Europe.
Former president Viktor Yanukovych's refusal to sign the Association Agreement with the EU last November triggered the protests which led to his overthrow. Interim prime minister Arseniy Yatsenyuk travelled to Brussels to sign political provisions of the agreement on Friday, with the EU committed to finalising the economic elements soon.
Speaking after the signing ceremony, Yatsenyuk said a military response to Russian incursions was ruled out because it was "not really acceptable for the world to have a Third World War".
"What is happening in the world today? What's up? Russia decided to actually impose a new post-Cold War order and to reverse the results of the Second World War. This is the truth," he continued.
He recognised that there would be an economic cost for standing up to Russia, but added: "We all need to pay the price for peace, stability, security and values.
"I strongly believe that the EU acknowledges this, realises this, and the EU will speak in one single and strong voice, protecting values, defending the territorial integrity of Ukraine and protecting the EU itself, because God knows where is the final destination - is it Ukraine or is it the EU?
"This deal meets the aspirations of millions of Ukrainians who want to be part of the EU."
European Council president Herman van Rompuy said the agreement signed today "recognises the aspirations of the people of Ukraine to live in a country governed by values, by democracy and the rule of law, where all citizens have a stake in national prosperity. And the popular yearning for a decent life as a nation, for a European way of life."
He added: "It shows our steadfast support for the course the people of Ukraine have courageously pursued."
The measures relating specifically to Crimea are thought to include a requirement that exports from the Black Sea peninsula to the EU carry a Ukrainian - rather than Russian - customs stamp.
US president Barack Obama stepped up action against Moscow yesterday by putting billionaire oligarch businessmen - including Putin's banker Yury Kovalchuk and his long-time friends Gennady Timchenko and Arkady and Boris Rotenberg - as well as the Russian president's chief of staff Sergei Ivanov on a list of regime figures who will face sanctions from America.
But opposition leader Alexey Navalny - a former candidate for Moscow mayor - said there should also be sanctions against oligarchs who have made a home in the West, such as Chelsea FC owner Roman Abramovich.
"Real sanctions, such as blocking access to their plush London apartments, will show that Mr Putin's folly comes with serious costs," wrote Navalny in the New York Times.