Furthermore, they argue, international practice at the time was that all territorial cessions included an extended surrounding area equivalent to the length of two cannon shots. When the treaty of Seville was concluded between Great Britain, France and Spain in 1729, long arguments ensued between Spain and Britain as to how far north the 'undoubted right' of Britain extended from the north face of the Rock of Gibraltar. It was finally accepted that a distance of 600 "Toises", being more than two cannon shots distance between the British guns and the Spanish guns, would be considered “the neutral ground”.