There are currently two main views on the ancestry of David Thomson in Thompson genealogy circles.

David Thomson born in England
Until perhaps very recently, the most commonly accepted view is that Thomson was born to parents in Clerkenwell Parish, which was just outside of London at the time (it is now well within Greater London limits). A parish baptismal record has been found attesting to the fact that a "David Tomson", son of "Richard Tomson", was christened on December 17, 1592 in St. James Church located there:

Clerkenwell is thought to have been home to Sir Ferdinando Gorges as well, and it appears this coincidence has led to speculations that either one or both of David's parents were servants in the Gorges household, or that David was apprenticed to Gorges for scribal or messenger services. This view also has David accompanying Gorges-organized expeditions to New England between the years 1605 and 1620, even as young as 14-years-old. Then in 1622, Thompson is given command of his own expedition, along with supreme authority to oversee Council for New England affairs in North America, and a significant grant of land from the Council's New England holdings.

There are a number of problems with this view:

• In many contemporaneous references to David Thomson in documents and letters, he is frequently called a "Scotsman" or "Scottish". Unless he was actively promoting himself as such, it seems the most likely reason for people to make that assertion would be that he had a distinct Scottish accent. But if he had been born and raised in southern England, and working with Englishmen all his life, it would seem unlikely that he would have acquired a pronounced accent, even if his parents were originally from Scotland (and proponents of this view make no claim and offer no evidence of this origin).
• Also in those contemporaneous references, Thomson is often referred to as a "gentleman". It is important to understand that in the 17th century, the term had much more significance than it does today. A gentleman was a member of the gentry, even if it was one of the lowest ranks of nobility. This category included, for example, the younger sons of baronets, knights, and esquires. This is not a title one could claim as the son of a servant or yeoman. And to claim such a title in the 17th century without unquestionable entitlement to it was a serious offense that could have legal consequences for the claimant.

  

• Regarding the baptismal record above, the spelling of the family surname in the Clerkenwell Parish registry is the English form - TOMSON. While this could have been an error on the part of the priest making the entry, it is cause for thought.

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  It is known that David Thomson signed his name as THOMSON, a Scottish form of the surname. If he were trying to create a Scottish persona when in fact he was English, this would be a natural adoption on his part. But if this deception was intentional, why the elaborate ruse to appear to be Scottish, especially at a time when the Scots were looked upon with suspicion by many in English society due to the recent accession to the English throne by the Scottish King James VI in what is known as the Union of the Crowns in 1603, a dynastic development that many English peoples were reluctant to accept?
• Thomson seemed exceptionally well educated for someone born of common parents. While serving as an apprentice to someone like Gorges would have offered significant educational opportunities over those normally available to the son of a servant, Thomson's education seemed exceptionally wide-ranging. He was adept with the chemicals and chemical formulations of the time and apparently worked as an apothecary as a young man, which would have required an apprenticeship not normally bestowed on members of the lower classes. He was said to be an expert navigator and chart maker. He was fluent with several European languages and was said to be proficient with a number of native American languages, so much so that his involvement was frequently sought in dispute resolutions between native American and English colonial groups throughout New England. And, some of his correspondence suggests he was either a lawyer, or at the least, considered to be quite knowledgeable about the law.
• Thomson's correspondence with other members of the English nobility conveys the sense that he is on somewhat equal societal footing with them. The level of deference that one might expect from a person not a member of noble society is not apparent in his writing.

David Thomson born in Scotland
An alternative view in development over the past couple of decades makes the case that the David Thomson involved in Council for New England affairs and the European settlement of North America was actually born in Scotland, in the parish of Corstorphine outside of Edinburgh, to parents of the Scottish nobility. This view is largely the product of research done by writer and journalist, and Thomson descendant, Genevieve Cora Fraser.

Fraser has gathered evidence that can be summarized as follows:

• On September 29, 1602, David Thomson of Corstorphine was admitted into the University of Edinburgh, with a scholarship to be paid out of the funds of the Kirk of Carraile, a powerful church in the royal burgh of Carraile, which had as part of its mission the support of students of philosophy and natural history at the college of Edinburgh.1
• His father, the Rev. Richard Thomson, was a wealthy minister with connections to the Scottish royal house of King James VI, and was granted several royal stipends to administer affairs at a number of parishes in Scotland and the Borders areas, with at least one of those appointments presented by King James himself.2
• Rev. Richard Thomson's second marriage to Agnes Foulis provided David with a number of significant family connections to members of the Scottish and English nobility, and especially to a senior administrator in the government of Scotland, Thomas Hamilton, 1st Earl of Haddington, who would later serve as one of several surrogate Governors of Scotland when King James moved to London after the unification of the thrones of England, Ireland, and Scotland (Union of the Crowns) in 1603, following the death of Elizabeth I of England.3
• As mentioned earlier, contemporaneous records from the period that are still in existence consistently refer to him as either "Scottish" or a "gentleman" or both. These references exist in both documents created in England prior to his exploration and settlement in New England, and in journal accounts with others involved in early New England settlement.4

For a much more detailed presentation of Fraser's evidence, her four-part series in the quarterly journal, The Scottish Genealogist, is available below.