From a Thompson family history:

 

In 1604 Sir Ferdinando Gorges, an intimate of Lord Essex,
was appointed Governor of Plymouth, England. With others, he

became interested in American discovery. In 1606 he obtained
from King James incorporation of the Plymouth Company with a
grant of land, fifty miles inland, between 40 and 45 degrees
North Latitude.
Between 1606 and 1622, numerous expeditions were sent out
to establish a settlement in America but for various reasons
no permanent settlement was established. Meanwhile, in 1620,
101 Pilgrims, under Governor Carver established a settlement
in Gorges' domain.
On October 16, 1622, the 'Council for the Affairs of New
England in America' granted to one David Thomson "6000 acres
of land and one Island in New England". The grant was signed
November 16, 1622. Thomson undoubtedly was a man of standing
in Plymouth and doubtless enjoyed an honorable position with
King James. On July 13, 1613, he had married Amyes Colle, a
daughter of William and Agnes (Briant) Colle, in Plymouth.
Though there is no evidence to the effect, it is probable
that David Thomson had engaged, in one capacity or other, in
one or several of the earlier expeditions to New England. In
any event, it appears that he had been in the employ of the
‘Council’, in a confidential capacity, as their agent.
Thomson conveyed a one fourth part of the island to three
merchants of Plymouth, Abraham Colmer, Nicholas Sherwill and
Leonard Pomery, with covenants for conveyance in fee simple
of a one fourth part of the 6000 acres of land. On December
14, 1622, an indenture was signed, between David Thomson, of
Plymouth, of the one part and these three Merchants, also of
Plymouth, of the other part, the provisions of which were in
substance as set forth below. (A verbatim copy of the indenture
may be found in New Hampshire State Papers, Vol. 25, #2
of Town Charters, pages 711 - 739, published in 1895).
lst: The three Merchants will, at their own charge, this
present year, provide and send two men, with David Thomson,
in ship 'Jonathan of Plymouth’, to New England with victuals
and provisions, etc. as shall suffice them till they be landed.
If they land within three months after passing Ram Head
(a promontory just outside Plymouth harbor), the residue of
three months victuals shall be turned over to David Thomson,
to be disposed of toward finding a fit place for the intended
habitation and to begin the same.
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2nd: The three Merchants will this year at their expense
provide and send three more men in "Providence" of Plymouth,
the charges to be equally borne by all parties.
3rd: The three Merchants will send 2 more men this year,
in the "Jonathan", the charges to be borne by all parties.
4th: As soon as Thomson and the seven men are landed, he
shall find a fit place for a choice of 6000 acres and also a
place to settle and erect houses or buildings for habitation
and begin same. Adjoining these buildings shall be allotted,
before the end of five years, 600 acres which with all buildings,
and everything appertaining to them shall, at the end
of five years be equally divided between all parties and all
charges shall be equally borne by all. The residue of 6,000
acres to be divided, in convenient time, between the parties
in four parts, Thomson to have three fourths, and the other
three one fourth.
5th: At the end of five years, the island shall be divided
in four parts, Thomson to have three parts, the others
to have one part.
6th: Three fourths of the charges for planting, husbanding
and building on the island shall be borne by Thomson and
one fourth by the other parties.
7th: All profits during the five years on the 600 acres,
by fishing, trading, etc. shall be divided equally, only the
Merchants shall have the liberty to employ ships to fish, at
their own charge, if Thomson does not bear his share.
8th: All the benefits and profits during the five years,
on the residue of 6000 acres and on the island, shall be divided
among them, Thomson to have three parts and the others
one part and each on request shall deliver a just account of
his receipts and payments during the five years.
In the Spring of 1623, David Thomson, with Edward Hilton,
his brother William Hilton and others set forth for America.
Upon their arrival, as was decided before they left England,
they first settled at a place they called Little Harbour, on
a point of land, now called Odiornis Point, on the west side
of the Piscataqua River, near its mouth. There David Thomson
remained, but the Hiltons established themselves further up
the River, at Cocheco, since named Dover. At Little Harbour
the first house was built. This was probably not Mason Hall.
In September 1623, Captain Robert Gorges, son of Sir Ferdinando,
with a commission from the Council for the Affairs
of New England in America to be their Lieutenant General, or
General Governor of the country, with Master W. Morrill, an
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Episcopalian minister and sundry passengers and families arrived
in Massachusetts Bay to begin a plantation. But Gorges
found things not to his liking. He stayed only a short time,
then returned with some others to England.
The island in Massachusetts Bay acquired by David Thomson
was the only Bay island which had a boat harbor. Comprising
an area of 157 acres, it was situated about eight miles from
Weymouth, slightly more than a mile from Braintree and about
a mile from Dorchester. It was named after Thomson and still
bears his name.
Tradition says that, in 1619, Thomson examined the harbor
islands, in company with Masconomo, sagamore of Agawam, (who
later made an affidavit to that effect), seeking a suitable
place to establish a trading post, and chose this island. In
1620, Myles Standish came hither with one William Trevour, a
sailor of the ‘Mayflower’ and named the island ‘Trevour’. He
later made an affidavit which stated that he took the island
in the name of Mr. David Thompson, gentleman, of London, who
soon afterward secured a grant. In 1623, David Thomson, then
of Piscataqua, acquired the island from Trevour.
Within a year after Robert Gorges had returned to England
David Thomson moved from Piscataqua to this island, where he
built a house, probably the earliest in Boston Harbor. Meanwhile,
the Council for the Affairs of New England in America
had designated him, in Gorges’ stead, Acting Governor. Thus,
from 1624 until his death, David Thomson occupied the honorable
and responsible position of Governor of all settlements
made in New England, under the oversight of the Council, by
virtue of the patent granted to the Plymouth Company.
David Thomson died on his Island in December 1628, at the
age of 36 years, from which it would appear that he was born
about 1592. Not long thereafter his widow and her infant son
John moved from the Island, and the Massachusetts Bay Colony
took possession. It remained idle until 1634, when Massachusetts
granted the Island to Dorchester.
In 1630 Governor Winthrop noted: "On Noddel’s Island (now
East Boston), lives Master Samuel Maverick. On this Island,
with the help of Master David Thomson, he had built a small
fort, with four great guns to protect him from the Indians”.
David Thomson's widow soon married this Samuel Maverick,
and they lived at East Boston. In a notarial record of 1646,
John Thomson, the only child of David called Samuel Maverick
(his step-father) ‘father’. On November 25, 1649, Nathanial
Maverick made an agreement to repay his father, Samuel, "all
monies that the latter should pay to John Thomson for him".
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In Court proceedings, May 3, 1648, in which John Thomson
undertook to regain possession of Thomson's Island from Dorchester,
it was recorded as follows - "upon the petition of
Mr. John Thomson, sonne and heire of David Thomson, deceased
that the said David Thomson, in and about the year 1626, did
take actual possession of an iland in the Massachusetts Bay,
called Thomson's Iland and **** dyinge soone after, left the
petitioner an infant, who, so soone as he came to age, did
make his claim formerly, and now again **** this Court ****
doe hereby graunt the said iland, called Thomson’s Iland, to
the said John Thomson and his heires for ever."
John Thomson eventually lost the Island by foreclosure of
a mortgage, February 15, 1657, to two Bristol merchants. In
testifying in Court, October 21, 1659, as witness to a will,
John said that he was ae. about fortie years. So he probably
was born about 1619.
In Braintree, a mile distant from Thomson’s Island, there
lived a shoemaker, named Thomas Thayer, whose second son was
named Ferdinando, after Sir Gorges. He was one of the pioneer
settlers of a new plantation in 1662 at Nipinuck, which
later was called Mendon. There he moved, with about 25 or 30
men from Weymouth and Braintree. One of the leaders of this
group was John Thomson. The first reference to him in Mendon
records was May 22, 1662. He obtained a grant and was one of
the 15 heads of families who settled in Mendon in 1664.
Although some doubt has been expressed that the Thomsons,
of Mendon, Massachusetts, were descended from David Thomson,
of Thomson’s Island, the Acting Governor of the whole Colony
of New England, the facts set forth above, with the will of
John Thomson, who died in Mendon in 1685, which is referred
to hereafter, seem to prove conclusively that David Thomson
was, in fact, the.emigrant ancestor of the Mendon Thomsons.