France has elected Francois Hollande as its first Socialist president in nearly two decades, marking a shift to the left at the heart of Europe.
Hollande unseated Conservative Nicolas Sarkozy in a heated election on Sunday, making the incumbent France's first one-term president since Valery Giscard d'Estaing lost to Socialist Francois Mitterrand in 1981.
The 57-year-old gave a rousing victory speech in Tulle, focusing on uniting France on several issues, after taking 51.62 per cent of the vote.
"To those who haven't voted for me - let them know that I hear them, and that I will be president to all. There is one France, united in the same destiny," said Hollande, who vowed to be dedicated to the causes of justice and youth.
Hollande, for whom financial policy in the wake of a European debt crisis was a major campaign issue, also said that he intended to implement promises of a more "pro-growth" policy.
"Europe is watching us, austerity can no longer be the only option," he said.
Al Jazeera's Andrew Simmons, reporting from Tulle, said that there were high expectations of a man who "has never even held a junior ministerial post".
"He's certainly proved popular despite a background that really is pretty boring, politically," said Simmons
Joyful crowds gathered in Hollande's adopted home town of Tulle and in front of the Socialist party headquarters in Paris, as news of the result spread.
Al Jazeera's Jacky Rowland, reporting from Paris, said: "A very clear, very decisive margin there, and already, we're seeing the scenes - cars hooting as they drive down the Champs-Élysées ... and crucially, the Place de la Bastille, the traditional celebration ground of the socialist movement."
Sarkozy, meanwhile, has suggested that he would step back from frontline politics after his failed re-election bid, but stopped short of confirming his retirement.
"In this new era, I will remain one of you, but my place will no longer be the same," he told supporters.
"My engagement with the life of my country will now be different, but time will never strain the bonds between us."
Earlier, Sarkozy urged his party to remain united. "Stay together. We must win the battle of the legislatives," he said.
France's parliamentary elections are due in June.
Hollande, who led in the polls throughout the campaign, won the April 22 first round with 28.6 per cent to 27.2 per cent for Sarkozy - making the right-winger the first incumbent to have lost so far in the first round.
Grey skies and rain showers greeted voters across much of France on Sunday, but turnout was high, at 80.3 per cent of the 46 million eligible to vote, according to interior ministry figures.
Sarkozy had vowed a surprise, while Hollande cautioned against assuming he will be France's first Socialist president since Mitterrand left office in 1995.
The election was marked by fears over European Union-imposed austerity and economic globalisation, and Hollande has said his first foreign meeting will be with German Chancellor Angela Merkel - the key driver of EU budget policy.
Hollande has promised more government spending and higher taxes - including a 75 per cent income tax on the rich - and wants to renegotiate a European treaty on trimming budgets to avoid more debt crises of the kind facing Greece.
That would complicate relations with Merkel, who championed the treaty alongside Sarkozy.
Under Sarkozy, France pledged to rein in its spending while the rest of the 17 countries that use the euro embark on a strict period of belt-tightening.
In France, that has included programmes designed to reduce government employment.
Hollande will need a strong mandate if he is to implement his proposed programme to fight EU-driven austerity measures.
Jose Manuel Barroso, the chief of the European Commission said, following Hollande's victory, that he shared the president-elect's goal of jumpstarting Europe's economy.
Al Jazeera's Nick Spicer, reporting from Berlin, said that Merkel had earlier made it clear that she would have liked to see a Sarkozy victory.
Our correspondent added, however, that there was a plan in place for Germany to work with Hollande, and Merkel congratulated the president-elect during a phone conversation on Sunday evening, inviting him for early talks in Berlin.
In comments made in Berlin on Monday, however, she said that the European Union's fiscal pact, which Hollande has criticised, "is not negotiable".
She has added, however, that she will welcome Hollande "with open arms" when he enters office.
Little known outside France, Hollande will soon have his diplomatic skills tested, with a Chicago NATO summit in late May and a Group of 20 summit in Mexico in late June.
Barack Obama, the US president, said that he looked forward to working closely with Hollande, and invited him for talks at the White House later this month.
The heads of state of several European countries, including the United Kingdom, Spain, Belgium and Italy, also congratuled Hollande on his victory, and pledged to work with him. [For a more comprehensive round-up of world leaders' reactions, click here.]
World markets, meanwhile, opened sharply down on Monday, following Hollande's victory in France and, more crucially analysts say, the change of government in Greece.