Grand Duke Guillaume swore an oath to ascend to the throne of Luxembourg on Friday in a traditional ceremony attended by royals and European heads of state.

Church bells rang out just before hundreds crowded outside the Grand Palace began chanting “Guillaume, Guillaume” as the new grand duke walked onto a balcony to greet his new subjects.

Grand Duke Guillaume, 43, wearing an olive-green military uniform with a yellow sash, was flanked by the royal family, including his wife, Grand Duchess Stéphanie, in a sky-blue gown. They carried their two children — designated heir Charles, 5, and 2-year-old François — both clad in shorts.

Just moments earlier Guillaume had taken the throne after swearing the sovereign's oath in Luxembourg's parliament.

He takes over from his father Henri, 70, who had served for 25 years in the largely symbolic role.

The crowd gathered outside the yellow stone and ornate turrets of the palace carried photographs of the new grand duke and duchess, others flags of Luxembourg and the red lion and orange fields of the Royal House of Nassau.

Some people had their faces painted in the Luxembourg flag: red, white and light blue.

All across the old city of Luxembourg, storefronts boasted portraits of the royal couple and blue banners commemorated “Trounweissel” or “ascension to the throne” in Luxembourgish.

Royals from the Netherlands and Belgium attended the ceremonies. Later on Friday, the new grand duke hosted an evening gala for guests including French President Emmanuel Macron and German President Frank-Walter Steinmeier.

Guillaume is Luxembourg’s seventh grand duke since 1890, when the modern monarchy was established. On Saturday and Sunday he will tour his new realm, a tiny duchy — the size of Rhode Island — of 700,000 citizens in the heart of Europe.

The tour will end with a Sunday Mass with Archbishop Jean-Claude Hollerich at the Catholic Notre-Dame de Luxembourg cathedral.

Cleaved from part of what are now France, Belgium and Germany in the 17th and 19th centuries, the small nation is a parliamentary democracy with the grand duke as head of state, akin to King Charles in the United Kingdom or King Philippe in Belgium.

Roughly 700,000 citizens speak a mix of Luxembourgish, a Germanic language, and French and German in public life. It is the world’s last remaining grand duchy.

One of the European Union’s smallest nations and its richest per capita, Luxembourg is a financial powerhouse that hosts important EU institutions like the European Court of Justice and the European Investment Bank.

The grand duchy is home to many of the banks in the eurozone, reinsurance companies and managers of hedge funds and money markets.

Guillaume will be Luxembourg’s seventh grand duke since 1890, when the modern monarchy was established.