A portmanteau (from 16th century French, plural portmanteaux) is a large travelling case made of leather. Originally designed with two sides with the hinge in between, one side to carry (porte) your coats (manteaux) and the other side for other items. The portmanteau could stand on end, so that the coats are hung vertically, and open up like a book to make a pair of mini-closets joined by hinges.