Legless, the term commonly used for drunks came about during the first World War. A scrawny boy soldier in the trenches was suffering from a nasty case of shock, when him commanding officers decided he needed a stiff drink. They gave him some of the home brew that was made in that time, which everyone knows is incredibly strong. Shortly after, the entirety of this particular trench was told to go 'over the top' in a mission to return some of this sweet sweet liquer that had been stolen the previous day. This boy, was far to drunk to do so, but tried anyway. He was stumbling around in no mans land when some german soldiers shot both of his legs clean of. This boy was immediately immobalised, but instead of screaming with pain, was singing a song similar to 'Knees Up Mother Brown', his commanding officers spoted him, and said to one another 'Look at that legless drunk.', hence the term.
Being legless, or drunk, originated in 13th century Chester. In order to repel Welsh raids, it was important for all men able to handle a longbow to be ready for action at any time of day or night. After a particularly lax defence of the city, in which the mayor had his finest robes pierced by no less than thirty-eight ineptly fired arrows, the drinking of 'stronge ales, liqors or other brewd drinkes (ande we neede to include bye name Mrs Filbert's finne scrumpie, whiche is finne indeede but doth sende menn blinde, or so itt is saide)' was banned by mayoral fiat.
Why an Italian car of dubious build quality was felt to be more effective than passing a law is a mystery lost to the ages, but we do know the punishment was having your legs chopped off - and then being left to run away from the Welsh on your own next time.