Lieutenant General Chris Brown CBE was more than three times the legal alcohol limit when he was breathalysed by police at the 4-star Dryburgh Abbey Hotel.
The 65-year-old from Hampshire had lodged a special defence of post-incident drinking, claiming he had drank a bottle of whisky within 15 minutes after returning to his hotel room.
But following a trial at Selkirk Sheriff Court he was found guilty of driving with a breath/alcohol count of 78 microgrammes – the legal limit being 22 – near the hotel on October 20 last year.
He was fined £500 and disqualified from driving for 12 months.
However, Lt Gen Brown was cleared of a series of other alleged offences on the day of the incident.
He was found not guilty of two assaults, threatening or abusive behaviour and failing to comply with a preliminary breath test after no case to answer submissions by defence lawyer Ross Dow.
Lt.Gen. Brown was last general commanding officer in Northern Ireland before the post was downgraded in 2008 and was deployed as the senior British military representative in Iraq as part of a multi-national force the following year.
He retired from the army in 2010 after serving for 36 years including the wars in Bosnia and Iraq.