"There is one thing very particular to them, that they do not cover themselves with bed-cloaths, but lay one feather-bed over, and another under. This is comfortable enough in winter, but how they can bear their feather-beds over them in summer, as is generally practised, I cannot conceive."

This was written by Thomas Nugent, a English travel writer in 1749 Westphalia.

Duvets are still commonly used in Europe (especially in northern Europe where it is the most common form of bed covering), and have become popular throughout the world in the late 20th century. Duvets reduce the complexity of making a bed, as it is a single covering instead of the combination of sheets, blankets, and quilts or other bed covers, which is traditional in many parts of the world. The cover is called a "duvet cover" or a "quilt cover". In modern times, a duvet is sometimes filled with silk, wool, cotton, or artificial fibers (such as polyester batting or other artificial material); it is sometimes confused with a comforter. Although comforters go on top of the traditional sheets and blankets, and are primarily decorative in nature, duvets are used by themselves. In some European countries any thick, warm blanket is subject to being called a duvet, as this has become a popular name for these kinds of blankets. In Australia a duvet or down quilt is often called a "Doona", which is a genericized trademark (registered to the Tontine Group) which is derived from the equivalent common Scandinavian term dyne and popularized by the retailer IKEA in the 1970s.

Originally the term continental quilt was the standard name used across Australia, and some regions continue to use this term. In Pakistan, duvets are known as ralli quilts, and are mostly used in the southern province of Sindh. In the US, confusion often occurs as the word "duvet" is sometimes used to refer to a comforter cover rather than the down blanket itself. For example, this is how the term is used by a large retailer:"For those of you enjoying a down comforter, or even just looking for a change for your bedroom, a duvet could be the perfect answer. Since you will be placing your comforter inside the duvet, it is important that the appropriate size be selected." — Bed, Bath and Beyond, Sizing Up Your Bedroom. The term "Duvet day" is used in some countries to describe an allowance of one or more days a year when employees can simply phone in and say that they are not coming in to work, even though they have no leave booked and are not ill. The provision of this benefit became fashionable in the late 1990s with many larger companies in the UK.

info from wikipedia