Our History

Cross-Collecting as a Lifestyle
Prinsengracht 266 — home of the gallery since 2016

Semper Fidelis [ˈsɛmpɛr fɪˈdeːlɪs]:
Always true to our principles

I really questioned the gallery scene in The Netherlands for many years and always chose to do my own unique approach: a combination of old and new art with objets d’art: for years, I was rejected by local gallery associations because they only would accept single art movement representation galleries. The typical white wall fluorescent lighting feeling. During the last five years, forty percent of those galleries closed their doors.

Revival of the Eclectic

A few of the worlds best minds in the gallery, auction houses and art associations have recently written lenghty articles which conclude the same: the high-end art collector of the future is an avid world-traveller: who takes her of his que to purchase a new piece only from intuition, artistry, historical relevance and the joy and amazement it sparks… not to own an entire collection of only modern, only sculpture, only photography, etcetera…
You can choose to buy a modern artpiece today and the next time an Egyptian antique…

Design under the motto: “Home is where the art is”

Our Vision

To share that amazing “wow” feeling I have when I come accross world-class Fine Art or Luxury Interior that I know has great story line and artistic value is my passion.

Tertius Xavier van Oosthuyzen

Our Philosophy

Its all about the story: a team of specialists conducts profound research for all paintings and objects.


We appreciate the lasting legacy of the rennaisance man: from draughtsman to architect


Attention to details is key in the artworks that we curate to be a part of our collection


Unique and hidden details add to the romantic story of an artpiece; art is supposed to enlighten and inspire.

Tertius Xavier van Oosthuyzen – The Founder

A true DaVinci ‘renaissance man’ he endeavoured to be the best clog maker of Holland, run a refugee center for Dutch Government, became Holland’s Best Wedding Photographer, founded Restaurant Week South-Africa: donating proceeds to Streetsmart helping homeless youth, operates a seasonal art gallery in Gstaad, Switzerland and is now living his lifelong dream of an art collection representing the finest old masters and modern in a true cabinet of wonders gallery space along Amsterdam’s UNESCO world-heritage site canals: TERTIUS COLLECTION.

Tertius Xavier van Ooosthuyzen — Gallery Founder & Owner

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Visit our gallery in Amsterdam for an immersive experience into the world of TERTIUS COLLECTION


by Samuel Dejong


by Victor Muller

Gaulino Chair

by Antoni Gaudí

Dutch Skating Scene

by Dirk Jan van der Laan

Fruit Still LIfe

by Bartholomeus Assteyn

Round Mirror

by Atelier Regtt

Seascape with ships off ‘t’Sondt’

by Jan Beerstraten
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Art sourcing, interior styling and more — just let us know what we can help you with

Art Sourcing

Interior Styling

Worldwide Shipping

Furniture Sourcing


Casalto was created in 2017 in Brussels by architect Eric Willemart. The project was born from a childhood dream and combining by the love of beautiful materials with stacking games.

Distributed across into five collections, Casalto offers exclusive tables, lighting and accessories in earthenware, hand-blown glass, marble and precious metal.

Each collection will transport you into a world where imagination meets travel. Casalto will take you to Vienna, Havana, Saint-Malo, Paris or Soho. Our collections have been inspired by the atmospheres and spirit of these cities.

5 collections for resolutely different atmospheres. Welcome to the world of Casalto.

BD  – Jaime Hayon

Although born and trained in Madrid, he was forged as a designer with Fabrica, the breeding ground of creativity run by Benetton near the Italian city of Treviso, where he arrived in 1997, when he had barely turned 24, to work under Oliviero Toscani, who would soon put him in charge of the design department. It was at Fabrica that he first worked with BD on the Mail Me project.

Hayon Furniture

BD Art Editions – Antoní Gaudí

A company that has always attributed such great importance to the author of the designs could never forget the great figures in history. That is why the BD catalogue of contemporary creations has always included those by admired classical masters.

Gaudí Furniture

BD Art Editions – Salvador Dalí

A sheep with a drawer in its stomach, a chair that wears heels, these truly surreal works of art could only come from the mind of Salvador Dalí. Pioneering, avant-garde provocateur, Surrealist, as famous for his personality as his work, a true icon, his legacy remains unrivalled in the current century.



Chamber of Commerce: 34148547
Bank IBAN: NL73INGB0007172147
VAT: NL002222018B13


Prinsengracht 266
1016HH Amsterdam
The Netherlands


Chamber of Commerce: 86157671
Bank IBAN: NL14INGB0397885911
VAT: NL863879779B01