King Malcolm Canmore "gaif to the predecessour and forebear of my Lord Seytoun the surename of Seytoun... appearandlie be ressoun that the gentilman... possessit the landis of Seytoun for the tyme... thay landis ar callit Seytoun for ane grit caus, becaus thay ly hard upon the Sey cost and the Toun thairof is neir to the Sey."

Seat of Scottish Seton's of Seton: The Knights of Seton, Baron's and Lords Seton and Tranent, Winton and Winchburgh, and Earls of Winton, etc.

The centerpiece of the Seton Family was the castellated Palace of Seton, standing on the same spot on the Seton baronial lands for upwards of eight hundred years, and where the original castle was a square tower built during the time of Seier de Seton sometime after 1066.  It was continually rebuilt and expanded by the successive heads of the family, becoming a castle-complex, after the time of William Seton, 1st Lord Seton, c1348. The property was put up for sale and sold again in 2008 by the MacMillan's, the developers who purchased it from the Wemyss Estate in 2003. Stephen Leech, the Internet Entrepreneur purchased the property for £5 million, and who then has placed it for sale in 2019 for £8 million.

The Palace, and now Castelled-House, stands in the middle of a large plantation of trees, of at least twelve acres, with a large garden to the south, and another to the north. The house formerly consisted of three large fronts of freestone, and in the middle was a triangular court, written as:

"The front to the south-east hath a very noble apartment of a hall and drawing room, a handsome parlour, bed chamber, dressing room, and closet. This apartment seems to have been built in the reign of Mary, Queen of Scots; for on the ceiling of the great hall are plastered the arms of Scotland, with the arms of France on one hand, and those of Francis the Second, then Dauphin, with his consort, Queen Mary, in one escutcheon, on the other; the arms of Hamilton, Duke of Chateauherault [Chatelherault], with several other noblemen's arms and supporters, with the French order of St. Michael round them. The front to the north seems to be a much older building than this.

The apartments of state are on the second story, and very spacious; three great rooms, at least forty feet high, which they say were finely furnished, ever since Mary, Queen of Scots, on her return from France, kept her court there: also two large galleries that were filled with pictures; but on my Lord Winton's forfeiture, all these were sold by the commissioners of inquiry, or stolen by the servants; and now there is not a whole window on that side of the house. The third front is full of good lodging rooms, but all out of order: at every angle of the house, and on each side of the gate, are handsome towers.

There are a great many offices in the outer courts, and a handsome church or chapel, where are some old marble monuments. The situation of this palace is very fine, and in the middle of an estate of five thousand pounds sterling a year, and the three towns of Cockney [Cockenzie], Tranent, and Long Nidry [Longniddry], where the tenants live, each within half a mile of his seat; and the whole estate he could see from his windows."

It was George, 6th Lord Seton, under James V, who was responsible for the splendid re-creation of the Seton House, and Mary de Guise, the French wife of Scotland's King James V, was often present. Prior to this, the Seton's had been much involved in the affairs of Scotland's Royal Family, having the privilege of their presence on many occasions, over successive generations, with the family's munificent tastes being much sought after by the Scotland's Monarch's as a place of relaxation and refuge.

The Palace continued to be enlarged to become a more commodious residence to serve the Royal Court, with a military character and Italian and French styling and courtyards. However it wasn't until after the "rough wooing" by England's King Henry VIII that it became known as the "Palace of Seton": the magnificent Palatial gallo-scottish residence by the 6th Lord Seton, and continued by his son and heir, the famed George, 7th Lord Seton, and continued still by their heirs the 1st and 3rd Earls of Winton.

George 7th Lord (called 5th of that name, referring to that of 'George') "repaired the forepart of the house of Seton, and especially that room called Samson's Hall (40 feet in height), which he adorned with a roof of curious structure, whereupon are twenty-eight large achievements, being those of Scotland, France, Lorraine, and the noble families that were allied to his family, curiously embossed and illuminate — the most exact pieces of armories that are to be met with...". The magnificent Palatial gallo-scottish residence was continued by the 1st, 3rd and 4th Earls of Winton's, until it was attacked, burned and looted by the Lothian Militia in 1715.

The property went to the York Building Company, which managed the estate and the coal woarking and saltpans, but the company went bust, and the house was left a ruin. The estate and castle were finally sold to a young lawyer and Lieutenant Colonel of the 21st Dragoons, Alexander Mackenzie who's father held the Portmore estate near Eddleston in the Borders. He commissioned the famed Architect Robert Adam to tear-down the Palace and rework the property into a new smaller mansion-house in Adam's 'new Castellated-style'. However the fraudulent nature of the MacKenzie sale was realized and the Estate was to be resold, albeit too late to save the old Palace. Following Mackenzie’s death in 1796, the Palace and much of East Lothian fell into the hands of the Earls of Wemyss, and who descendants held it until 2003.

Very little remains standing of the original Palace, except perhaps for the current main-house block which was re-worked from the rear addition of the Palace, along with some of the vaulted basement sections, Robert Adam re-using it's stone and fragments of the various building-structures for the new "castle" seen today. The new mansion, a somewhat imposing but simplistic castellated edifice of four storeys, has a large outer walled courtyard and two extensive two-storey wings, and sits in 15 acres of grounds.