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Currently the Mayor of Luxembourg City, the 40-year old been formally designated as "formateur" by Grand Duke Henri, the country's head of state. This means he's in charge of forming a coalition government with the Greens and Socialists and if all goes to plan he'll become Prime Minister within the next few weeks.

Although Luxembourg is a tiny country of just 540,000 people it plays a major role in the European Union, meaning Bettel is likely to become a major figure in Brussels.