"Ton" and "tonne" are both derived from a Germanic word in general use in the North Sea area since the Middle Ages (cf. Old English and Old Frisian "tunne", Old High German and Medieval Latin , German and French "tonne") to designate a large cask, or "tun". A full tun, standing about a metre high, could easily weigh a tonne. An English tun (an old wine cask volume measurement equivalent to approximately 954 litres) of wine has a relative mass of approximately 954 kg if full of pure water, a little less for wine.