The former RAF squadron leader was among the Capital's best-known historians, and wrote several books about the city he loved.
Born in Edinburgh in 1909, Dr Barclay was educated at the Royal High School and Edinburgh University, and would later teach at both institutions for many years.
During the 1930s he served as deputy head of the Edinburgh School of Salesmanship, a precursor to Napier University and Telford College, where he pioneered the use of slides as teaching tools, taking many of the photographs himself.
It was not long before the outbreak of the Second World War, and Dr Barclay would serve for several years as a squadron leader in East Anglia, where he taught servicemen and women at RAF bases.
When he returned to his home town he taught at the Royal High School, before becoming deputy and later acting director of the Department of Adult Education and Extra Mural Studies at Edinburgh University, where he would work from 1953 until he retired in 1975.
It was there that he would hold an afternoon and an evening lecture every Monday, often on the history of the city, for more than a decade.
His daughter Alison said that they were so popular that the university allowed him to use the new George Square Lecture Theatre.
She said: "People flocked to see his lectures because he was such an incredible teacher. The lecture theatre can hold 600 people and it was always packed.
"He had an incredible knowledge of the city, and he expected me to as well.
"I remember as a girl him taking me up Calton Hill and listing every single spire and rooftop in the city, he knew what every single one of them was."
Dr Barclay was also an avid fan of film, and he was a founding member of the Scottish Educational Film Association, now known as the Scottish Screen department at the National Library of Scotland.
He also served as a Boys Brigade Officer for 20 years, and in his retirement he was also president of the Gilbert and Sullivan Society of Edinburgh and president of the Old Edinburgh Club.
Dr Barclay also had a flair for journalism, and edited Newspeak, a talking magazine for blind people in the Lothians for 20 years.
He spent his final years at the Strachan House residential home, owned by the Barchester group, for whom he edited the company-wide magazine for nine years up until his death.
Alison said: "He was halfway through the 38th edition of the magazine, which is widely read across the company, when he died.
"My father had enjoyed his time at Strachan House, and the staff there were fantastic.
"When he had his 100th birthday party at the home six of the directors, including the managing director, came up, because he was so widely respected.
"He had an incredibly active mind and made the magazine a success. Even up until this year he was often called up by people writing about the city because of his knowledge.
"He also embraced technology and we got him a laptop for his 100th birthday.
"He lived his life educating people. Even though he had a long and full life, he will be sadly missed by many."