Mr Robertson was born in Dundee and studied law at Dundee University. He was admitted as a solicitor in 1972 and joined Fergusson, Robertson, Stephen and Norrie, becoming a partner in 1976. The firm became Thorntons following a merger in 1990 with Thornton Oliver.

He became chairman in 1997 and served in that role for 20 years.

A quiet and unassuming man, he was held in great affection by the legal community.

Thorntons chairman Colin Graham said: “His colleagues and his clients meant everything to Jack and he looked after them all with a client care uniquely of his own making.

“He was an immensely talented and knowledgeable technical solicitor but also knew how to navigate and resolve practically the most difficult of problems and seemingly impossible conflicts between parties.

“He was a mentor, a confidante and a sounding board and was always generous with his time and wisdom in resolving legal or personal problems for anyone in the firm and beyond.

“He was genuinely a wonderful man and Thorntons and the wider community is a poorer place with his passing.

“We are all privileged to have worked with him, to have known him and been friends with him.”

Mr Robertson is survived by his wife, four children and six grandchildren.