The contact between Italian city states and the Ottoman empire was strong and frequent, and many luxury goods traveled back and forth - food, luxury fabrics, horses, falcons, spices, jewellery, books. The kaftan was the ultimate symbol of power and respect in the Ottoman empire, and the quality and price of a kaftan given as a diplomatic gift determined how high a status this visitor had. The zimarra fashion might have originated with Ottoman imperial and ambassador gifts brought to Italy. Curiously, the Ottoman kaftan fashion was only picked up by women in Italy, apart from some few examples of Italian gentlemen dressing in Turkish fashion for their portraits. 

The garment emerged around 1530, and was made very popular in Florence by Duchess Eleonora di Toledo, wife of Cosimo de’ Medici in the 1540s. She had multiple zimarre in her wardrobe - the surviving Medici Guardaroba lists 79 zimarra and 14 roba, some 93 loose overgowns in total, most made of satin or velvet, and she is seen wearing them in many portraits and depictions. They were also vastly popular in Venice, the city state with the closest contact with the Ottoman empire. 

By the late 15th century they went out of fashion, replaced by the tighter fitting French veste/roba and the doublets preferred by youngsters. Unlike the zimarra, the veste and doublets had waist seams, and often puffed sleeves. Along with the new invention of the corsets, they helped re-shaping the torso and contributing to the sometimes extreme silhouettes favourited by the late 16th and early 17th century. But earlier in the 16th century it was all about the loose, flowing lines, and for that the zimarra was a perfect garment. 

The zimarra continued to be in use in Europe after the 16th century. But then as an informal dressing gown, leading up to the modern wrap dressing gowns which got its inspiration from Japanese kimonos rather than Ottoman kaftans. 

It’s thought the name zimarra is related to the Greek word for winter coat - Χειμαριός (chimarios). Much of the population in Constantinopel/Istanbul was Greek, and the island of Crete was an Italian colony in the 16th century, which makes the Greek name a plausible origin. A similar Spanish garment was called redondas. In the 17th and 18th century, zimarra like dressing gowns for men were called banyans or “Robe de Chambre”.