The family of Hay has many branches throughout Scotland, and trace their history back to the 12th century, some writers say to the 10th century. Tow notable families, the Earls of Errol and the Marquesses of Tweeddale, bear this family name. Sir Gilbert de la Haya was created High Constable of Scotland by Robert the Bruce, and the office was made hereditary in the family of the Earls of Errol, who obtained the lands of Slains in Aberdeenshire. The Errol family engaged actively in the affairs of state and were concerned in the religious troubles of the times. William, 9th Earl, had to sell part of his estates to pay for his magnificent style of living. He died in 1636. On the death of the Countess of Errol in 1758, the title passed to her grand-nephew, John, Lord Boyd, 15th Earl, who changed his name to Hay. The 16th Earl was created a baron of the United Kingdom, by the title of Baron Kilmarnock of Kilmarnock. He died in 1846.

Sir William Hay, Sheriff of Peebles, who was descended from the same stock as the Earls of Errol, married the eldest daughter of Hugh Gifford of Yester, and founded the family of the Hays of Yester. John Hay was created Lord Hay of Yester in 1488. John, 8th Lord Hay of Yester, a man of outstanding ability, was created Earl of Tweeddale in 1646. The Tweeddale family were conspicuous in their defence of national religion and liberties, and John, 2nd Earl, was created Marquess of Tweeddale in 1694.

Crests: A falcon rising, proper. A goat’s head erased, argent, armed