The origins of the family business date back to the late 19th and early 20th centuries, when Michelangelo (Angelo) Zegna (1859–1923), a watchmaker from Trivero, Biella, decided to open a textile factory in the nearby town of Flecchia.

[7]Zegna's vision was to create high-quality fabrics, so he began to source wool directly from several countries around the world, such as Mongolia, Australia, South Africa;[6] he also bought modern machinery from England.

[6][8] Sales and marketing departments were also established in France, Germany, the U.K., and the U.S.[6] In 1972, Zegna launched its made-to-measure service called Su Misura.

[11][12] The international development strategy run by the Zegna brothers brought to the openings of the first owned boutique in Paris in 1980, followed by Milan in 1985.

Angelo's son, and namesake of the company's founder, Ermenegildo "Gildo" Zegna, became CEO of the Group in 1997;[14] his cousin Paolo became the chairman.

Starting from the late 1990s, the Group has undertaken a series of acquisitions of Italian and foreign companies that have expanded its business scope and now form the “Filiera”, a unique, company-owned and controlled entity, comprising selected Italian textile producers, integrated with the distinctive manufacturing capabilities of luxury, ensuring excellence, quality, and innovation.

In 2009, the Ermenegildo Zegna Group acquired a majority stake in Tessitura di Novara, a company specialized in high-quality silk weaving.

[18] In 2012, it acquired a minority stake in Pettinatura di Verrone, a company specializing in the combing of fine wools and natural fibers.

[22] In 2018, Zegna – already present in India with three stores – together with Reliance, acquired a stake into Indian fashion designer Raghavendra Rathore's firm.

[23] In the same year Zegna announced that they purchased 85% of the eponymously named Thom Browne, a New York City-based menswear and womenswear brand, founded in 2001.

[24] In 2019, Zegna bought a 65% stake of Italian jersey fabrics manufacturer Dondi, increasing its control over the textile supply chain.

[25][26] In June 2021, the Zegna Group bought a 60% majority stake in Tessitura Ubertino, a high-end fabric maker based in Piedmont.

[27] A few weeks later, Zegna also bought a 40% share in Tessitura Biagioli Modesto, an Italian spinning mill specialized in cashmere production.

[29] In 2021, Zegna agreed to go public by combining with a US special-purpose acquisition company launched by European private equity group Investindustrial.

Under the Zegna Group supervision, shorn fleeces coming from several countries are processed at the Lanificio, combining artisanal activities and modern technologies, from raw material to finishing.

[49] Founded in 1932 by Luigi Baldi in Pernate, a fraction of the municipality of Novara, it is a silk-weaving company specialized in the production of cashmere, pure silk, and high-end natural fabrics.

Based in Sagliano Micca (Biella), Cappellificio Cervo is a historic hattery (founded in 1897) acquired by Zegna-controlled ZECA company in 2018,[54] with the aim of relaunching it, in partnership with entrepreneur Vincenzo Caldesi and Artigiana Cappellai.

[65] In 1993, the Oasi Zegna was established in the Biellese Alps, a natural area of 100 square kilometers where over 500,000 conifers were planted in the late 1930s during the construction of the panoramic road.

It is a comprehensive archival center that houses documents, photographs, technical drawings, sample books, and objects generated over more than a hundred years of industrial activity.