Centuries-old roots in the Grand Duchy.
A family at the heart of Luxembourg
The family that today carries the name d'Ansembourg has two stems, both rooted in the Mosan ironmasters of the early seventeenth century. The Bidarts came first: in 1624, Thomas and Nicolas Bidart, from Dinant, acquired forge and furnace rights on the seigneurie of Ansembourg, and Thomas Bidart's family moved into the medieval castle. The Marchants, ironmasters of Bouvignes-sur-Meuse just upriver — documented in that town from 1431 — followed three years later, when Hubert Marchant bought the forges of La Trapperie at Habay-la-Vieille in 1627. The two lines joined in 1652 by the marriage of Thomas I Marchant and Marguerite Bidart.
Within a single century their descendants would unify the entire seigneurie of Ansembourg, enlarge a new château beneath the medieval fortress, and rise — by the Habsburg sovereigns of Luxembourg — to baron, then count, and finally count of the Holy Roman Empire.
The d'Ansembourgs are an old family by Luxembourg standards, and a young one in the deep European sense — newcomers, really, who arrived as ironmasters in the early seventeenth century and stayed. This history is set down not to look back, but because the story belongs to Luxembourg as much as it belongs to the family — and because in a small country, a family's memory is part of the country's memory too.
A family in pictures
Stones, faces, gardens, gatherings — a few images from the family's archive. (More will be added over time.)







Six centuries · at a glance
Where the family has lived
Every castle, forge and seat the family has held — across Luxembourg, Liège, Dutch Limburg and Westphalia. Click any marker to read its story.
A quiet claim
Many noble families once held land in what is now the Grand Duchy. When Luxembourg separated from Belgium in 1839, most of those families — seated in Arlon, Bastogne, Marche or further west — passed to Belgian nationality with the territory. The d'Ansembourgs, seated at Ansembourg in the canton of Mersch, remained.
As best as can be told, they are the last titled house whose noble dignities were granted in Luxembourg, by the sovereigns of Luxembourg, on Luxembourg soil — and which stayed on this side of the border in 1839. The fact is worth naming, not to rank one family above another, but because it is part of the country's history; a family that does not name its own continuity makes it easier for everyone to forget.
A fortress of the fourteenth century… there is a ghost… an extraordinary glow… I thought of Hamlet's words to Horatio. Victor Hugo, on visiting the ruined Old Castle of Ansembourg, 1871
The family chronicle
For decades the family has kept its own internal yearbook, the Cahiers d'Ansembourg — a handsome, large-format chronicle of births, weddings, anniversaries, articles, photographs and memoirs. Twenty-four issues are gathered in the family's private area, where they can be read and searched.
Family members may request the password from the editor — see Contact.