Sorry, that I just know the German name, it is called a “Rechteckmantel” which basically translates to rectangular cloak. It was worn from the bronze age into early medieval times in Europe. It is basically as others pointed out just a rectangular piece of wool fabric, much like a blanket. It can be used as such when travelling.

The “Rechteckmantel” used to be closed with a brooch or a pin and could be worn in various ways. The one in the picture for example is of someone who expects to have to use their right arm for working or drawing a weapon. But one could also close the cloak in the front with a bit more overlap for more warmth but that would limit movement by a lot.

It is a very comfortable piece of clothing. I have a hobbyist interest in living history and my “Rechteckmantel” served me well during many cold nights.