In February 1558, George Seton was one of eight commissioners sent to Henry II of France to negotiate the marriage of Mary, Queen of Scots, to the Dauphin.

Seton, the Earl of Huntly and Châtellerault were asked to meet the people of Edinburgh to discuss the restoration of Mass in St Giles.

[6] In Paris in October 1560, he secretly met the English ambassador, Nicholas Throckmorton, asking him for a passport to return to Scotland through England.

After a delay of a few days, Seton left France in November 1560 (presumably with the finished portrait),[7] accompanied by an archer of the Scottish Guard called Alexander Clark, whose loyalty Throckmorton thought he had bought.

During the personal reign of Mary in Scotland George had a loyal inscription set in large carved letters and gilded above the entrance to Seton Palace;"UN DIEU, UN FOY, UN ROY, UN LOY"One God for all time: One loyalty to the monarch.

[12] Thomas Randolph, the English diplomat, heard that Mary and Lord Darnley went to Seton Palace and were "bedded" after their marriage at Holyroodhouse.

[14] The French ambassador, Jean, Count de Brienne, arrived in Edinburgh on 2 November 1566 and was lodged in Henry Kinloch's house in the Canongate near Holyrood Palace.

[15] Days after the death of Lord Darnley, on 17 February 1567, Mary had a blue costume for her fool called George Steven delivered to her at Seton Palace, in April she was there with her council.

[16] With other supporters of Mary's marriage to James Hepburn, 4th Earl of Bothwell Seton signed the Ainslie Tavern Bond on 19 April 1567.

The son of Lord Ochiltree, John Knox's brother-in-law, would have killed him in revenge for his father's injury, but he yielded and was saved by James Stewart, 1st Earl of Moray.

Seton was to ask for Spanish help to re-instate Mary in Scotland and expel her son's supporters who depended on English power.

Seton tried to convince Alba to provide an army of 10,000 men by persuading the Scottish soldiers fighting against Spain to change sides.

[23] Meanwhile in Scotland, the goods of his French stepmother, Marie Pieris, and half-brother Robert Seton were seized by Regent Moray's officers.

[26] An Italian called Battista di Trento wrote a long letter to Elizabeth I of England in 1577, which alleged to reveal a plot some years earlier involving Seton and his sons, including Alexander, then a student in Rome.

Battista laid out five schemes for the plot and the 19th century editor of William Cecil's papers believed his circumstantial details to show some "sub-stratum of truth" in his statements.

His son John Seton of Barnes, known as the 'Cavalier de Bucca' from his post at the Spanish court, had returned to Scotland and was suspected to have brought messages from the exiled Queen Mary.

He said he was to continue the league and amity with France, follow the advice of the Duke of Guise, and complete the treaty with her and her son (a plan for her return to Scotland in joint rule known as the "association").

[31] Seton was funded in part by the town of Edinburgh, who gave him a commercial mandate and contributed 2000 marks to hiring of Andrew Lamb's ship.

[33] On 21 June 1584, Stafford remarked in another letter that Seton's phrases echoed those of Mary, Queen of Scots, and it was clear the two maintained frequent communication.

[37] On 22 June 1586, his son Alexander, Prior of Pluscarden, returned to Edinburgh council copies of their papers regarding French import duties sent with George to Henry II.

[38] George was buried at Seton Collegiate Church and his memorial has a lengthy Latin epitaph which also describes his children's careers.

[41] According to Richard Maitland, Hamilton of Sanquhar organised some of the rebuilding of Seton Palace, which had been damaged by the English army that burnt Edinburgh in May 1544.

Above the fireplace in the Great Hall were carved his coat of arms quartered with the Earl of Buchan encircled with a collar which Nisbet claimed to represent the Order of the Thistle.

The ceiling of another room, called Samson's Hall, incorporated 28 armorial achievements of families of France, Scotland and Lorraine, "curiously embossed and illuminated.