cardigan

A cardigan is a knitted top that opens down the front with buttons. The one you put on over everything else and never quite take off.

It is named after the Earl of Cardigan, who led the Charge of the Light Brigade and whose officers wore knitted waistcoats in the Crimea. That gives English two garments named after that one war, since the balaclava comes from the same campaign. What separates a cardigan from a jumper is simply the opening, since a jumper goes over your head. British informal speech shortens it to cardi.