Thomson descendants of King Robert II (Stewart)
1 Robert II - 1390 = Elizabeth Mure (parts of Corstorphine had belonged to the Queen's family)
...2 Prince Alexander (Steward) Earl of Buchan
......3 Alexander Stewart - Earl of Mar - 1435
.........4 Sir Thomas (Stewart), Knight - Bef 1435
............5 father of Alexander Thomson (literally son of Thomas)
...............6 Alexander Thomson (1460 - 1513 said to be the grandson of Alexander Earl of Mar, died at Flodden)
= Margaret Forrester (great-grandchild of Sir John Forrester of Corstorphine, Lord High Chamberlain)
..................7 Alexander (Stewart) Thomson d. 1587 Corstorphine m. Janet Gourlay
.....................8 Bernard Thomson - 1600 = Agnes Balzert
........................9 Rev. Richard Thomson, Magister 1564 - 1606
(mother of David unknown, Richards' second wife =  Agnes Foulis)
...........................10 David Thomson 1587/88 - 1627 = Amias Colle
..............................11 John Thomson 1619 - 1685 = Sarah Trevore (based on scribbled marriage entry, her father, Captain Trevore, came to John's rescue when he was trying to claim Thomson's Island)
In 1602, David Thomson of Corstorphine, son of Rev. Richard Thomson received a bursary (scholarship) to attend the University of Edinburgh as a Philosophy major. In the "New English Canaan" Thomas Morton refers to Mr. David Thomson as a traveler and scholar conversant with the Indians. David's father Rev. (Magister) Richard Thomson's ecclesiastical appointments were from King James (possibly as a distant relation, see chart above). He also received preferential treatment in terms of large sums of money each year for his services and was given a second lucrative assignment on the Borders at the time of the King's journey into England after Queen Elizabeth's death.
David's father Rev. Richard was the Clerk (legal position) at the Kirk Assembly in 1605 and was put in a position of siding with his King or everyone else. He sided with the King which resulted in several clergyman having to go to trial in England, many were exiled. Richard may have been a witness at the trial. He died at the time of the trial. His nephew-in-law Thomas Hamilton was the lawyer for the King. The King owed him big-time.
David Thomson's step-mother, Agnes Foulis (widow of Rev. Adam Hepburn), was aunt to David Foulis, the Scottish ambassador to England who was also closely associated with the Earl of Sterling (William Alexander) as both served in the court of King James' son Prince Henry who died at the age of 16 years. There is a 1637 letter from the Earl of Sterling to Governor Winthrop expressing his concern that Amias and Samuel Maverick are not treating David Thomson's son John properly by using what David had worked so hard for their own benefit (clearly the Earl of Sterling, a Scotsman knew David well. He succeeded Thomas Hamilton as Secretary of State of Scotland). David Foulis' father-in-law was the mayor of London. (That is...The King's ambassador to England, David Foulis' uncle was David Thomson's father, the Rev. Richard Thomson.)
Agnes' niece married Thomas Hamilton, later the Earl of Melrose and Haddington. He was the Secretary of State of Scotland under King James as well as at the time of Thomson's Piscataqua grant and his being named Governor of Massachusetts on behalf of the Council for New England (1622). There are letters showing a close working relationship between David's father and the future Secretary of State for Scotland, Thomas Hamilton. David Thomson's step-brother, Adam Hepburn, was the legal clerk to Thomas Hamilton in 1622 at the time of Thomson's grant. (That is...The Secretary of State of Scotland, Thomas Hamilton's uncle-in-law was David Thomson's father Rev. Richard Thomson and David Thomson's step-brother works for him at the time David and Amias prepare to settle in New England. David Thomson's step-brother later became a Senator.)
David Thomson was ordered by the Council for New England to appear before the King's Privy Council (a high privilege) while Sir Ferdinado Gorges was ordered to address Parliament to explain why it appeared he was trying to acquire a monopoly.
The document naming Thomson acting Governor under the Massachusetts grant refers to him as Mr. David Thomson, Gent. It was a criminal offence to pretend you were a gentleman if indeed you were not. One of the chief signers of the Massachusetts grant is Thomas Howard, the Earl of Arundel, the Earl Marshall for England. In his position as Earl Marshall, Arundel was in charge of heraldry matters. If David was not a gentleman (a man of high rank...as opposed to opening doors for ladies) he would have thrown David into prison if he pretended to the title of Gentleman. (Mr. may also have referred to Master as in Master of a ship otherwise the term Gentleman at the end of his name is a redundancy. In the letter to Arundel, Thomson appears to be a Master of the ship in the sense of being in charge... which may or may not mean he was also the Captain.)
David's three page letter of July 1625 from Plymouthland is addressed to the Earl of Arundel, one of the highest ranking peers in England, 2nd only to the King's cousin the Earl of Lenox who also appeared to be on good terms with David Thomson. The letter makes clear that though David is deferential, they are on intimate terms. His references in the letter to family hunting practices would be indicative of Scotland, not England. In fact, King James of Scotland was known to have hunted in Corstorphine prior to his assuming the crown in England in 1603... as did James, the Marquise of Hamilton who also signed the Massachusetts grant. David Thomson is of Corstorphine also associated with the Canongate. The seal that is believed to be David Thomson's seal displays a stag's head with a cross pattee between the antlers. That is also the heraldic sign of Canongate. Rev. Richard Thomson was associated in his ministry with the Kirk of Canongate.)
People who knew David referred to him as a Scotsman and a Gentleman, and according to Morton he was a Scholar too. Doesn't sound like he was born in London, the son of a household servant to Ferdinando Gorges... at least not to me. If he were born in London, he would have had the accent of a Londoner and not high born either. Both the high and low ranking describe Thomson as a Scotsman. I suspect his Scottish accent gave him away. Also, he signs his name DAVID THOMSON in the 1625 letter. That is the Scottish spelling!
There are many more supporting reasons why David Thomson of Corstorphine is the same David Thomson who settled in New England, but it would take a book to explain it all. These are merely a few highlights.