When Robert reached the age of sixteen he became a Burgess of the City of Aberdeen. Among other benefits, this entitled him to follow a merchant's trade in the town. During the next few years he attended Marischal College, graduating in 1689. Soon afterwards he left Aberdeen for Europe. Like many Scots at the time, He travelled far and wide around Northern Europe before finally settling on Danzig (modern Gdansk) where he established himself as a merchant trader. Over the next few decades he built a highly successful business and soon became wealthy. By 1692, he was rich enough to donate a large sum of money to his old college and by 1699, it appears that he was providing low interest loans to landowners in Aberdeenshire who needed working capital.
Little more is known about his time on the Baltic but by 1720 at the latest, he returned to Aberdeen, a very wealthy man. However he had never married and had no heirs. Consequently he decided that his fortune would be used to found ‘a hospital for maintenance, aliment, entertainment and education of young boys’ and wrote his will to that effect. He started work on the project in 1730. He died shortly thereafter -- of overeating it is said -- but the project had started, funding was still there, owing to his foresightedness, and work continued on his dream.
Construction of the building was completed in 1743. However before it could be used for its intended purpose, it was taken over by the Duke of Cumberland to use as a barracks for the Hanoverian troops on his visit to Aberdeen in 1746 to put down the Jacobite rising, and so the hospital, which later became Robert Gordon's College did not open until 1750.