Dubbed “the last emperor” in a documentary film of the same name released in 2008, and “the Sheik of chic” by John Fairchild, the former editor of Women’s Wear Daily, Mr. Garavani founded his namesake company in 1959. For the next half-century, he not only dressed a world of grandees but also became their equal, with his own palaces, movable court and signature shade of red.