Born in Ayr in 1942, he was admitted as a solicitor in 1964 and was made partner at Robertson Chalmers & Auld in 1967. He became a temporary sheriff in 1977, a floating sheriff of North Strathclyde at Paisley in 1979 and then resident sheriff at Glasgow in 1981.

He sat in Glasgow for 24 years before he was appointed sheriff principal of South Strathclyde, Dumfries & Galloway in 2005. In 2015 he was appointed as an appeal sheriff in the Sheriff Appeal Court.

He became the first solicitor to sit in the High Court after being appointed as a temporary high court judge in 2008.

Sheriff Lockhart defended the independence of the judiciary in 2015 when former Police Scotland chief constable Sir Stephen House questioned another sheriff’s suggestion that a cover-up culture existed in the single force.

Scott C. McMaster, captain of Pollok Golf Club, of which Sheriff Lockhart was a member, said: “He was a rather successful sportsman including rugby, cricket, squash, tennis and of course golf. He was a particularly respected figure in the legal profession … with almost 40 years on the bench as a sheriff and latterly as a sheriff principal.”

Mr McMaster added that while Sheriff Lockhart “had not golfed much in the past few years”, he was “still a regular attendee for lunch at the club”.

He added: “My thoughts at this time are with his wife Christine and his children Abbey, Heather, Richard and Douglas and all his family and friends.”