Original lounge chair by Flemming Lassen, Denmark.

Architect Flemming Lassen was as noted for his furnishings as he was for his buildings, and he created bedroom furniture and other pieces specifically for the inviting interiors he brought to fruition. The Danish modernist is credited by many for his role in introducing his native country to functionalism, which prioritizes practicality over excessive ornamentation in design. Lassen is widely known for his comfortable, plush vintage sofas, lounge chairs and other seating, such as the overstuffed Tired Man armchair and Mingle sofa.

Lassen's mother and father were both painters. In the early 1900s, he and his brother — architect Mogens Lassen — began to attend boarding school where they befriended Arne Jacobsen, with whom Flemming would come to share an affinity for the principles of functionalism. Jacobsen became a leading light of Scandinavian modernism — his celebrated mid-century designs include the Swan chair and the Egg chair — and he and Flemming remained close throughout their lives, maintaining a strong personal relationship as well as a professional bond as like-minded colleagues.

Lassen and Jacobsen exchanged ideas and collaborated — the former shared his friend’s holistic approach to building projects, which is evidenced by Jacobsen’s design for the SAS Royal Hotel in Copenhagen. Jacobsen’s designs for the property encompassed everything from the architecture to interiors and furnishings. Together, Lassen and Jacobsen won an award at the “Architects Building and Housing Exhibition,” which was held at the Forum in Copenhagen in 1929. The duo was recognized for its “House of the Future,” a circular structure fitted with a then-revolutionary automatic garage door opener and windows that rolled up and down with a handle — just as they would in a car. The House of the Future has influenced Danish architecture to this day.

Flemming also often collaborated with his older brother Mogens, designing buildings and furniture alike. Mogens designed all kinds of tables and seating, and worked with the likes of Jacobsen, Finn Juhl and Ole Wanscher on various projects.

Flemming Lassen created the oak-and-sheepskin Tired Man armchair for The Copenhagen Cabinetmakers’ Guild Competition in 1935. Three years later, he designed the Mingle sofa. Both seating pieces are very popular with collectors today.

Find vintage Flemming Lassen furniture on 1stDibs.