kaftan

A man’s robe, usually reaching to the ankles, with long sleeves. Silk and velvet kaftans were worn by sultans, princes and high officials during the Ottoman Empire. (Also spelled: caftan). Web resource here.

UntitledOttoman Child’s Kaftan with Detachable Sleeves.  Brocaded silk.  16th century. Topkapi Museum, Istanbul, Turkey.