The family history is closely linked with that of Kilsyth.
The history of the family of Edmonstone of Duntreath, written by Sir Archibald Edmonstone, 3rd, Bt., was finished in 1851. It was published privately in 1875, four years after his death, as a memorial to him.
The family had close, at times conspiratorial relationships with the Livingstons of Kilsyth.
In 1614 Sir James Edmonstone - the original owner - mortgaged the whole of the Duntreath estate to his son-in-law Sir William Graham of Braco, redeemable on the payment of 80,000 merks. In the same year however, the mortgage was made over to Sir William Livingston of Kilsyth, but not on quite the same terms, as some portions, for which 20,000 merks were paid, were alienated for ever, including presumably Colzium and Kilsyth.
However, the Livingstone family lands in Scotland, and their seat at Colzium, were forfeited after the Jacobite rising of 1715. This letter written in 1721 proves that Sir Edmonstone was secretly and treasonably acting as Livingstone's agent in Scotland in the 1720's whilst he was in exile in Rome, and indicates that relationships were somewhat strained by financial matters.
Kilsyth Estate was bought by the York Buildings Company (a fraudulent enterprise which bought up Jacobite Estates) and was subsequently sold to Daniel Campbell of Shawfield, owner of the island of Islay. Returning from Ireland, the Edmonstones acquired the property which the Livingstons had been forced to sell. The sum which they paid for the East and West Baronies of Kilsyth, including the lands of Bancloich, in the parish of Campsie, was about £41,000.
The Livingston's castle of Colzium had been demolished in 1703, and the Edmonstones built Colzium House close to the earlier castle site, probably using the original stone. Duntreath was by then partly ruined and Colzium, for the next eighty years, became the Edmonstone family home, thereby completing a circle which had commenced in 1614. After they rebuilt Duntreath, the Colzium estate was broken up c.1920 and the house was sold by Sir Archibald Edmonstone, the 5th Bt. to Mr William Lennox Mackie in 1930. By then nearly derelict it was handed over by him to the people of Kilsyth in 1937, who restored the house and estate for the public benefit.
The family website can be found at: http://www.edmonstone.com/ - see below: