It is generally accepted that the master mason employed for the work was John Bell. The Bell family of masons gave Aberdeenshire an outstanding group of castles including, Crathes, Midmar, Drum and Castle Fraser. This partnership between the well-traveled, educated and wealthy, William Forbes, and the gifted master mason, John Bell, combined to create a tower-house, which, in its mature 17th century form, is perhaps Scotland's greatest contribution to European architecture.

In 1627, just one year after the completion of his castle, William died. He had lived in the brief respite of time between the Reformation and the Civil Wars, a special time during which the northeast of Scotland witnessed both economic and cultural vitality. He was succeeded by his son, also William, who was made a Baronet of Nova Scotia in 1630. Once Civil War broke out, Sir William was involved in many battles, leading the capture of Harthill Castle in 1640 and being captured at (and escaping from) the battle of Aberdeen in 1644. In 1647 he became the Sheriff of Aberdeenshire but died the following year.

In 1823 Sir John the seventh baronet, found the castle greatly in need of repair but deliberately chose to restore rather than change the castle by alteration or addition. This astute decision is perhaps the earliest Scottish example of protecting a building for its architectural and historic value; a supreme compliment to the earlier partnership of William Forbes and his master mason, John Bell.