Members of this distinguished lineage have held numerous prominent roles, including Presidents, Governors, Legislators, and military leaders.

The family name is derived from that of several villages called La Haye in the Cotentin Peninsula of Normandy, France.

The first is the Legend of Luncarty, which is an important Hay tradition, while the second is based on historical research, albeit that inconsistencies tend to occur after so many centuries.

In contrast, George Buchanan's account in his Rerum Scoticarum Historia, published in 1582 and derived from Boece's work, omits any reference to the hawk's flight delineating the land grant.

[26] "The traditional origin of the noble house of Hay is thus related:—In the reign of Kenneth III, anno 980, the Danes, who had invaded Scotland, having prevailed, at the battle of Luncarty, near Perth, were pursuing the flying Scots, from the field, when a countryman and his two sons appeared in a narrow pass, through which the vanquished were hurrying, and impeded for a moment their flight.

and he headed the fugitives, brandishing his ploughshare, and crying out, that help was at hand: the Danes, believing that a fresh army was falling upon them, fled in confusion, and the Scots thus recovered the laurel which they had lost, and freed their country from servitude.

The battle being won, the old man, afterwards known by the name of Hay, was brought to the king, who, assembling a parliament at Scone, gave to the said Hay and his sons, as a just reward for their valour, so much land on the river Tay, in the district of Gowrie, as a falcon from a man's hand flew over till it settled; which being six miles in length, was afterwards called Errol; and the king being desirous to elevate Hay and his sons from their humble rank in life, to the order of nobility, his majesty assigned them a coat of arms, which was argent, three escutcheons, gules, to intimate that the father and two sons had been the three fortunate shields of Scotland."

The evidence that the battle actually occurred, other than Bower's brief reference to it about 1440 AD, was described by Reverend Moncrieff[30] around 1791 in the First Statistical Accounts of Scotland.

These were not examined by professional archaeologists to determine whether they were consistent with the presumed date of the battle, as they would have been had the retrieval occurred in modern times.

Regarding the legend, Sir James Balfour Paul, noting that armorial bearings did not occur in Scotland till long after 980 (when the battle is said to have taken place), referred to Hector Boece as "an incorrigible old liar" in this and other stories.

Secondly, the Soulis name, rare in England, and the more common Hay, are both found in the records of Dover castle in the early 13th century.

[37] In consequence Edward I declared Gilbert a traitor, but Robert the Bruce rewarded him with a charter over the lands of Slains in Aberdeenshire and the office of Constable of the realm of Scotland.

Another Hay, also named Sir Gilbert, was a Scottish knight who fought for Joan of Arc during the Hundred Years' War.

[37] During the Civil War James Hay led his forces as Royalists against the Covenanters at the Battle of Aberdeen in 1644, where they were victorious.

Sir William Hay of Delgaite served with James Graham, 1st Marquis of Montrose as his chief of staff during his campaign in support of Charles I of England.

[37] He was succeeded by his sister, Mary, who used the ruins of their fortress of Old Slains Castle as meeting point for Jacobite agents and it was she who personally called out the Clan Hay to fight for Charles Edward Stuart.