Everything you need to know about France's new president

Emmanuel Macron, 39, will be sworn in on Sunday.

— LONDON -- When Emmanuel Macron is sworn in as the president of France on Sunday, he will be the youngest person ever to hold that position.

In his resounding electoral victory yesterday, Macron, 39, showed that France wants an alternative to established politics. But although he was relatively unknown in French politics three years ago and only founded his independent party, En Marche!, last year, Macron is not the outsider he may appear to be.

“This image of fresh, youthful energy has carried him to election, even if in truth Macron is no outsider but an archetypal insider as a graduate of France’s most privileged educational establishment, a former banker turned technocrat and government minister,” Jim Shields, professor of French politics at Aston University in Birmingham, England, told ABC News.

Born in the city of Amiens in northern France, Macron is the son of doctors and was raised in a well-off home. He went to a private Jesuit college in his hometown, then the elite Henri-IV school in Paris. He later studied philosophy at the University of Paris-Ouest Nanterre La Défense, before completing his post-graduate studies at the prestigious Sciences Po and the prominent École nationale d'administration, which France's current president, François Hollande, also attended.

Ahead, here is what you need to know about France's next president.

Hollande's former protege

Macron was Hollande's protege for years -- and after working as an investment banker for Rothschild & Cie Banque for four years, he became part of Hollande’s senior staff as deputy secretary general at the Élysée Palace.

In 2014, he was appointed economy minister. But in April of last year, Macron founded En Marche! in a move that was seen as a betrayal of his former mentor. Macron resigned in August. A few months later, he formally announced his bid for the presidency –- running on messages of hope, globalization and "democratic revolution."

Macron has described En Marche! as "neither left nor right," but rather an attempt to transform the political system, which he criticizes for being dominated by large interest groups.

The former banker has promoted both pro-business and socially liberal policies, giving him a centrist appeal that other candidates lack. However, opponents have criticized him for being a political novice while pointing to unpopular measures he backed during his tenure in government. Among those measures was a law dubbed the "Macron Law," which allowed businesses to open on Sundays.

In 2007, Macron married his former drama teacher, nee Brigitte Trogneux, who is 24 years his senior. When the two met, he was a teenager and she was married with children.

“At 17, Emmanuel told me, ‘Whatever you do, I will marry you’!” she told Paris Match magazine last year.

European relief

Sunday's victory over far-right, anti-EU candidate Marine Le Pen has not only been celebrated by Emmanuel Macron's supporters but also by members of the European establishment. They had been watching the election carefully, fearing that a Le Pen victory would have been a blow to the EU, which is already dealing with the UK’s planned departure.

“His program is very much embedded in the European project. He is one of the few European leaders who has been campaigning on a pro-European platform,” Françoise Boucek, a lecturer at the School of Politics and International Relations at Queen Mary University of London, told ABC News. “In terms of the European stage, people can settle down a little. Now, it’s going to be business as usual."

Shields described Macron as a “committed Europeanist” who believes not only in preserving the EU but in deepening it.

“He argues, for example, that the eurozone should have its own budget and finance minister,” Shields said. “In terms of France’s wider international role, for example in NATO, Macron’s approach will be one of continuity as opposed to the more isolationist proposals put forward by Marine Le Pen.”

Challenges ahead

Macron does not have much time to celebrate his victory -- many challenges lie ahead.

Some people voted for him because they didn't like the alternative –- others didn’t vote at all. At 74 percent, the voter turnout was the lowest since 1969.

“Macron as President will have to deal not just with the 1 in 3 who voted against him by supporting Marine Le Pen; he will also have to deal with the 1 in 3 who either abstained or wasted their vote as a protest against the choice on offer,” said Shields.

He also needs to prepare for parliamentary elections in June, which could have a crucial impact on his success as president. One of his most important tasks will be to improve the economy and create more jobs which he says he wants to do through reform. But that might be difficult if his party doesn’t win a majority in June.

“If he fails to win a majority there, his ambitions to reform France may need to be scaled back with the consequence that he could become yet another President elected on a promise of reform only to end up managing the status quo,” said Shields.

Rebooting the French economy is his most important task, said Boucek. But it is likely that he will not win a majority in June’s election and will have to form a coalition government – for example with left-wing parties that might not support his hopes for labor reforms.

“He says he is going ahead with this labor reform by decree if he has to,” said Boucek. ”But that’s sure to get people on the street.”