Emmanuel Macron became France's youngest ever president on Sunday, promising at his inauguration to restore the country's lost confidence and pledging to relaunch the flagging European Union.
Macron, a 39-year-old centrist, took the reins of power from Socialist Francois Hollande at the Elysee Palace a week after his resounding victory over far-right leader Marine Le Pen in an election that was watched worldwide.
After a private meeting with his former mentor Hollande and his first speech as president, Macron headed up the rainy Champs Elysees in an army vehicle, waving to small crowds of wellwishers who gathered along the famed avenue.
Macron said his first priority would be "to give back to the French people the confidence that for too long has been flagging", while the second would be making France a beacon for democracy and freedom worldwide.
France's place was in the EU "which protects us and enables us to project our values in the world," but he said the 28-member bloc needed to be "reformed and relaunched."
Macron also suggested he would press on with his ambitious but controversial agenda to reform France's rigid labour market and modernise the social security system despite the fierce resistance he is likely to meet.
"I will not reverse course on any of the commitments taken in front of the French people," he said, adding that "France is strong only if she is prosperous."
Some analysts and opponents have questioned the strength of Macron's mandate after he won just 24.01% in the first round of the presidential election on April 23 before his landslide victory over Le Pen in the second.
His opponents on the far-right and far-left, opposed to the EU and major economic reforms, won around 50% of the first-round vote.
Macron's first week will be busy. On Monday, he is expected to reveal the closely-guarded name of his prime minister, before flying to Berlin to meet German Chancellor Angela Merkel.
It is virtually a rite of passage for French leaders to make their first European trip to meet the leader of the other half of the so-called "motor" of the EU.
Pro-EU Macron wants to push for closer cooperation to help the bloc overcome the imminent departure of Britain, another of its most powerful members.
He intends to press for the creation of a parliament and budget for the eurozone.
Merkel welcomed Macron's decisive 32-point victory over Le Pen, saying he carried "the hopes of millions of French people and also many in Germany and across Europe".
Further ahead in June, Macron will need to win a majority in parliamentary elections to enact his ambitious reform agenda.