The Grand Duke of Luxembourg and his family, who's who

Luxembourg has a monarch, but not a king. Its head of state is a grand duke, the only one left anywhere, and since 3 October 2025 that has been Guillaume. For a British reader the set-up will feel familiar in some ways, a hereditary head of state with a largely ceremonial role, and quite different in others. Here’s the family, where the Grand Duke fits in the system, and the little of it a visitor can actually see.

Guillaume, Grand Duke since October 2025

Guillaume was born on 11 November 1981 at the Grande-Duchesse Charlotte maternity hospital in the capital. The Court sets out his education in some detail. He went to primary school in Lorentzweiler, then to the Lycée Robert Schuman and the Institut Le Rosey in Switzerland, spent 2001 and 2002 at the Royal Military Academy Sandhurst and graduated in Letters and Political Science from Angers in 2009. He speaks Luxembourgish, French, German, English and Spanish.

The handover was prepared calmly. On 8 October 2024 his father appointed him lieutenant-representative, a kind of stand-in with delegated powers, and on 3 October 2025 he took the oath as Grand Duke. According to the government’s official portal, he swore to uphold the constitution and the laws and to maintain national independence. Taking the oath also made him a general and commander of the army.

Trounwiessel, three days of a change of throne

Luxembourgish has its own word for the handover, Trounwiessel, and the capital marked it from 3 to 5 October 2025. The tourist office’s listings set it out hour by hour. On Friday 3 October there was Henri’s abdication ceremony at the Grand Ducal Palace at 10am, Guillaume took the oath before the Chamber of Deputies at 11am, the family stepped out on the palace balcony at 12.15pm, and at 1.25pm the new grand ducal couple met the public on place Guillaume II, between a reception at the city hall and another hosted by the government at the Cercle Cité. Saturday brought entertainment on the Glacis, a show on the Grande-Duchesse Charlotte Bridge and, after dark, a drone display and concerts. A Te Deum in the cathedral on the Sunday closed it.

What strikes me is the scale. A new head of state was installed in a single morning, with ceremonies an hour apart and a short walk from each other, and the rest was a street party. Palace, Chamber, city hall and cathedral all fit into one stroll round the Ville Haute, and walking it with that sequence in mind tells you a lot about how the monarchy works here.

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The family, from heir to uncles

The Grand Duchess is Stéphanie, born Countess de Lannoy, who married Guillaume on 20 October 2012 in Notre-Dame Cathedral in the capital. They have two sons. Charles, born on 10 May 2020, is the heir, and François was born on 27 March 2023. The Grand Duke has four siblings, Félix, Louis, Alexandra and Sébastien.

His father, Henri, was born in 1955 at Betzdorf Castle, in Betzdorf, and reigned from 7 October 2000 until his abdication 25 years later. He married Maria Teresa Mestre on 14 February 1981. The dynasty is Nassau-Weilburg, which came to the throne in 1890, when the Dutch crown went to a woman and the Nassau family pact recognised male heirs only. The family’s greater arms carry the Bourbon-Parma shield at their centre. The wider story is in history of Luxembourg.

How much power does he have?

Less than the title suggests. Under the constitution the country is a constitutional monarchy run as a parliamentary democracy, with the Grand Duke at its head. He promulgates laws and judgments are delivered in his name, but nothing he does is valid without a minister’s countersignature, and political neutrality is required of him. The EU’s own country page puts it bluntly, saying he has only formal rights. The person who actually runs things is the prime minister, covered in Luxembourg government.

There’s one detail I find very Luxembourgish. Officially, National Day marks the sovereign’s birthday, yet it always falls on 23 June, whoever is on the throne and whenever he was born. Guillaume’s birthday is 11 November. How the day is celebrated is in Luxembourg National Day.

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Where he lives and what you can visit

The family doesn’t live in the palace in the capital. The Luxembourg City Tourist Office makes it clear in its FAQs. Home for the family is Berg Castle, in the commune of Colmar-Berg, and it’s closed to visitors. What you can see is the Grand Ducal Palace on the Marché-aux-Herbes, with its Renaissance façade. It opens for a few weeks each summer for guided tours, where adults pay €18, children aged 4 to 12 pay €9 and under-4s go free. The 2026 season sold out, and the Court says the 2027 dates will be announced later.

At any other time of year the façade and its sentry box look just the same from the street. And on 22 June, the eve of the National Day, the city marks the evening with torches through the streets and fireworks launched from the Adolphe Bridge.

What I’d do as a visitor

For a visitor, Luxembourg’s monarchy is mostly a palace in the city centre and a couple of dates in the diary. I’d note two. The summer palace tour, booked through the tourist office on Place Guillaume II or online, which fills up, and National Day eve if your trip lines up. The family itself is easier to follow on the Court’s website than on the street.

So you do not lose the morning at the ticket office, browse tickets and tours in Luxembourg on GetYourGuide.

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Before you fix your dates, compare tickets to Luxembourg: the same journey can cost very different amounts from one day to the next.