Ottavio Missoni, who has died aged 92, was the co-founder of the Italian fashion brand Missoni and the patriarch of a dynasty.
In 1953, with his wife, Rosita, he set up the company that became known around the world for its brightly coloured geometric knits and zigzag patterns.
Ottavio, known as Tai, and Rosita began with a few knitting machines, making designs for other brands. The first Missoni collection appeared in 1958 and included two striped dresses that sold out in the Milan store La Rinascente. Adapting the Raschel knitting machine (which was usually used for shawls) in 1963, the Missonis created the distinctive zigzag lightweight knits which became their signature.
Their first fashion show was in 1966, and the brand began to grow in the 70s, with a colourful, bohemian aesthetic. Supporters included the influential fashion journalist Anna Piaggi and the American Vogue editor Diana Vreeland, who reportedly commented, on seeing the vibrant knits: "Who said that only colours exist? There are also tones."
Sixty years after its foundation, Missoni, based in Sumirago, in the countryside outside Milan, continues to be successful – it had a turnover of £59m last year, with 40 stores around the world and celebrity fans ranging from the Duchess of Cambridge to Jennifer Lopez. It has also expanded into homewear and hotels. This suited Ottavio perfectly. "I've never done what was fashionable," he said in 2011. "Going against the rules comes naturally to me."
The son of a sea captain, Vittorio, and his wife, Teresa De Vidovich, Countess of Capocesto and Ragosniza, Ottavio was born in Dubrovnik and grew up in Zadar – now part of Croatia but then Italian territory. He fought with the Italian army in the second world war at the Battle of El Alamein and was a prisoner of war in Egypt for four years.
He was also a talented athlete, who had competed in track events before the war. A member of the Italian national team at 16, he was a champion at the World Student Games in 1939. He continued exercising regularly into his 90s, and had a swimming pool and gym installed at his home. In an interview with Women's Wear Daily in 2011 he said: "Running was a natural gift. They called me 'son of Apollo'."
Sport turned out to be his unlikely entry into fashion. He represented Italy in the 400m hurdles at the 1948 Olympic Games in London, and made knitted tracksuits that were worn by members of the Italian team. Sixteen-year-old Rosita Jelmini was a student spectator at the event and the couple met at a lunch organised by the Italian team.
Married in 1953, they turned out to be a formidable fashion force. The Missoni brand combined Ottavio's burgeoning design skills with Rosita's background in textiles – her family had owned a shawl-making factory. They began with a small factory in Gallarate, Lombardy, where Rosita had grown up.
As with other Italian fashion houses, from Versace to Ferragamo, family has been central to the Missoni brand. Although Ottavio and Rosita continued to preside over its progress, in the 90s they handed over the day-to-day running of the business to their three children, Vittorio, Luca and Angela. Angela has designed the ready-to-wear collections since 1996. The couple continued to live near Sumirago and Ottavio devoted more time to painting and tapestry, also writing an autobiography, Una Vita sul Filo di Lana (A Life on the Woollen Thread, 2011).
Ottavio saw the evolution of the Missoni dynasty as a natural choice rather than something expected of the second generation. "I never pushed for them to pursue this career," he said, "but I'm happy because they chose the company themselves. And we all agree it's a family firm and it must remain as such."
Three generations are now involved in the business – Ottavio and Rosita's granddaughter, Margherita, designs accessories – and rather than using models, the photographer Juergen Teller has captured the family at home for ad campaigns since 2010.
Ottavio is survived by Rosita, their children and grandchildren. Their son Vittorio and his wife, Maurizia, have been missing since January, when their plane disappeared over the coast of Venezuela.
• Ottavio Missoni, fashion designer, born 11 February 1921; died 9 May 2013
guardian.co.uk © Guardian News and Media Limited 2010