Italian luxury king Giorgio Armani, head of a high-end lifestyle empire and one of fashion's most famous names, has died at the age of 91, sparking tributes to a fashion legend.

"The world lost a giant today. He made history and will be remembered forever," fellow Italian icon Donatella Versace said on Instagram.

The best-known contemporary designer, Armani opened his fashion house in Milan in 1975, quickly rising to the top of the industry and going on to dress the stars.