Romania's new president, Nicușor Dan, has been officially sworn in, ushering in a tentative close to the worst political crisis to grip the European Union country in decades after the annulment of the previous election but several challenges lie ahead.
Dan, a 55-year-old mathematician and former mayor of Bucharest decisively won the 18 May runoff, beating his hard-right opponent George Simion, who later challenged the results in the Constitutional Court but was rejected last week.
