The lands of the Mains, where the school is situated, were originally granted by the Earl of Lennox to Maurice Galbraith in the 13th century.

Thus, the Douglas family inherited the extensive lands of the Mains, and were elevated to Lairds of the estate in the same year by King Robert II of Scotland.

[5] The title became extinct in the 20th century; the last 33+1⁄2 acres (13.6 hectares) of the estate (including the house) was sold to Dunbartonshire county[6] and was subsequently used for the erection of the secondary school, Douglas Academy, in Milngavie prior to the death of the last heir, the 21st Lord of Mains, Lieutenant Colonel Archibald Vivian Campbell Douglas in 1977.

[citation needed] As part of an extensive PPP project (Public-Private Partnership) marshalled by the Scottish Government with £100 million funding, Douglas Academy has been rebuilt along with various other East Dunbartonshire schools.

The upper half, with its cross and roses, is part of the arms of the Burgh of Milngavie, while the lower half is the arms of Douglas of Mains, owners for many generations of the Mains Estate on which the school stands.