"Arco" Floor Lamp by Achille & Pier Giacomo Castiglioni for Flos, circa 1960s

It was a humble street light that inspired Achille Castiglioni (1918–2002) and his brother Pier Giacomo Castiglioni (1913–68) to design their Arco lamp. The two men, along with their eldest brother, Livio, were the sons of prominent Milanese sculptor Giannino Castiglioni, and all became trained architects. Achille graduated from the acclaimed Polytechnic University of Milan in 1944 and joined Pier Giacomo and Livio in the design studio they'd opened with Luigi Caccia Dominioni. With large architectural assignments hard to come by, the Castiglionis focused on small-scale projects. At the core of their design philosophy was problem-solving, creating objects that fulfilled consumer needs. Their motto was: “Start from scratch, stick to common sense, know your goals and means.”

With functionality a primary concern, the Castiglionis produced pieces inspired by the “readymades” of artist Marcel Duchamp. The Arco lamp was born out of a desire to create a fixture that illuminated like pendant lighting but didn’t require drilling into the ceiling and that could be moved as its owner’s interior evolved.

The initial Arco lamp, designed in 1962, had a marble base (weighing 110 pounds), a chrome ball shade and a long curved steel arm that enabled light to be projected from nearly eight feet up, as if from a chandelier hung overhead. In another ingenious touch, the Castiglionis drilled a hole in the marble base through which a broomstick could be guided to serve as a handle so that two people could move it.

The same practicality is evident in the other famed lighting pieces — including the Snoopy and Taccia table lamps — that Achille and Pier Giacomo designed for FLOS. The brothers began their relationship with the Italian lighting company in 1960, and it continues to make their signature pieces today.

Imaginative lighting is a longtime hallmark of modern Italian design. Following in the footsteps of innovative companies such as Artemide and Arteluce, the company FLOS brought a fresh aesthetic philosophy to the Italian lighting field in the 1960s, one that would produce several of the iconic floor lamp, table lamp and pendant light designs of the era.

FLOS — Latin for “flower” — was founded in the northern town of Merano in 1962 by Cesare Cassina (of the famed Cassina furniture-making family) and Dino Gavina, a highly cultured businessman who believed that artistic ideas espoused in postwar Italy could inform commercial design. The two enlisted brothers Achille and Pier Giacomo Castiglioni as their first designers.

Even before FLOS was formally incorporated, the Castiglionis gave the firm one of its enduring successes with the Taraxacum pendant and associated designs made by spraying an elastic polymer on a metal armature. (George Nelson had pioneered the technique in the United States in the early 1950s.) For other designs, the brothers found inspiration in everyday objects. Suggestive of streetlights, their Arco floor lamp, with its chrome boom and ball-shaped shade sweeping out from a marble block base, has become a staple of modernist decors. Designing for FLOS since 1966, Tobia Scarpa has also been inspired by the commonplace. His folded-metal Foglio sconces resemble a shirt cuff; his carved marble Biagio table lamp looks like a jai alai basket.

In 1973, FLOS purchased Arteluce, the company founded in 1939 by Gino Sarfatti, and it continues to produce his designs. In recent decades, FLOS has contracted work from several noted designers, including Marcel Wanders and Jasper Morrison. As instantly recognizable as they are, many FLOS designs remain accessible. While FLOS lighting is the essence of modernity, its sleek, subtle designs can be used to strike a sculptural note in even traditional spaces.

Browse a broad range of FLOS lighting fixtures at 1stDibs.