The duke, who is also the Hereditary Keeper of the Palace of Holyrood in Edinburgh, was three times over the legal drink-driving alcohol limit when he evaded police in a car chase, at speeds of up to 95 mph, on 20 December last year.
Police said lives had been in danger as the 54-year-old duke sped through villages during the chase around Haddington. He accelerated through police road blocks, eventually crashing into a road sign at high speed.
At Haddington Sheriff Court in East Lothian yesterday in addition to the driving ban the duke was sentenced to 12 month's probation and 200 hours community service.
With custodial sentences almost uniformly imposed in such extreme circumstances, the court's decision was criticised for exposing 'one law for the aristocracy and another for everyone else'.
Adrian Davies, director of the Glasgow Council on Alcohol, a voluntary agency which campaigns against alcohol misuse and offers counselling, said the sentence was 'just not right'.
Mr Davies said there was no excuse for the duke's behaviour and it should have been dealt with as a serious offence. 'If that involves a custodial sentence, so be it.'
In court, Raymond Fraser, for the duke, said: 'It is perhaps difficult for people who work hard and play hard not to do things to excess.'
He told Sheriff John Dean that on the same evening of the incident the duke had been taken to Edinburgh Royal Infirmary with a suspected heart attack. As a result, he had no recall of what happened later. On being apprehended he had knocked off a policeman's helmet and spectacles.