[2][3] Reginaldus de Camera, later Chalmer, is recorded to have held the Barony of Gadgirth as a hereditary possession,[4] during the reign of William the Lion (1165–1214).

[1] The family continued in residence until circa 1761 and in 1800 Colonel Joseph Burnett, retired from the East India Company, purchased part of the old barony, including Gadgirth and the Old Ha' Castles.

The name 'Chalmer' derives from the post of Lord or Great Chamberlain of Scotland, Camerarius Regii a position held by Herbert de Camera from 1124 to 1153,[5] a member of the family who were of Saxon or Norman descent.

[6] In 1424 John Chalmer of Gadgirth fought for King Charles VII of France against the English at the Battle of Vernuie and was awarded the right to use the Fleur de Lis in recognition of his gallantry.

[7] James Chalmer of Gadgirth was a great supporter of the Scottish Reformation and was regarded by Archbishop Spottiswood and John Knox as one of the boldest of the leaders of the movement.

The Chalmer's were connected through marriage with many families in Ayrshire and elsewhere, such as the Campbells of Loudoun, Hamiltons of Cadzow, Cuninghames of Caprington, Wallace of Ellerslie, Craufurd of Craufurdland, Fergusson of Craigdarroch,[13] Farquhar of Gilmilnscroft, etc.

[12] The Chalmer of Gadgirth coat of arms is Argent, a demi-lion rampant, Sable, issuing out of a Fess, and in base, a Fleur-de-Lis: all within a border, Gules.

Gadgirth Castle was itself demolished in 1808[15] when a new mansion house was built on its footprint by Colonel Joseph Burnett who had retired from his post with the East India Company.

[15][2][16] Extensive woodlands and a pale or fence are shown on Timothy Pont's map of the early 17th century indicating a deer park.

[18] A print of 1892 by the artist Robert Bryden shows a castle that has been given some Georgian features such as regular windows and ornamental bartizan towers.

The historian John Smith in the 1890s visited the site and recorded that even at that date only a short stretch of wall could be traced.

[2] Built in 1808 on a prominent position overlooking the River Ayr and Gadgirth Holm it was purchased in 1949 by the council became a children's home.

[3] As stated, the 1775 William Armstrong map appears to indicate a house rather than a castle with a road running to it via Enterkine and with a bridge across the River Ayr as confirmed by the name Bridgend.

The OS maps also record a monument or obelisk built in the centre of one of two old 18th century wooded roundel features[21] on top of the hill that lies above Gadgirth Mains.

John Thomson's map of 1828 indicates an ornamental lake in front of Gadgirth House in the Byre Burn Glen, however this is no longer shown in 1908.

[4] At least two coal pits are recorded,[27] one lying above Gadgirth Mains with some ruins remaining and the other with an engine house in the Byre Burn Glen.

[28] The Chalmer family in 1558 held 52 acres of lands at Thornlibank also known as Chalmerhouses located at the east end of the burgh of Irvine.