As noted in the section on James Mathews Jr. it is very likely that he was the oldest of his brothers. Trying to determine the birth order of the remaining sons is very difficult. One thing I am fairly certain of is that brothers Isaac and Charles were probably born consecutively (although which was first between those two is anyone's guess), brother Matthew was probably the youngest and Thomas was either the second oldest son or the second to youngest. For various reasons, however, I believe that Thomas was the second oldest son.
Unlike his brother James Jr. there is nothing extant that gives the least indication of when Thomas may have been born. From Albemarle Parish records in Surry county we do know that Thomas's son James was born 4 Aug 173987 so it is almost certain that he was born before 1719. He only appears in a couple of Virginia deed records. Curiously, he is remarkably absent from the deed books of Surry or Brunswick County, Virginia. His brothers appear in quite a few deeds, mostly as witnesses, as far back as the early to mid 1730s, yet we don't find Thomas mentioned in the deed books until the early 1740s. Is this an indication that he was a bit younger than James Jr., Isaac and Charles?
Surry County, VA patent and deed books show that Thomas obtained 200 acres from Isaac Hall in June 173888 and then a patent for 318 acres which adjoined the 200 acres in August 1743.89 The entire 518 acres was slightly north of the Nottoway River and was adjacent to his brother James Jr's 1745 patent and approximately a quarter mile west of his father's 1716 homestead plat. Due to the late dates at which both Thomas and James Jr. obtained these pieces of property it seems likely that neither was certain that they would permanently move to North Carolina (or perhaps the patent process was started before they knew that they would move). Around this same time frame both brothers were obtaining property in Edgecombe County, North Carolina.
Aside from deed records not much is revealed about Thomas in North Carolina documents. He first obtained 150 acres in 1744 on Little Fishing Creek from his brother James Jr. in that part of Edgecombe County that would later become Halifax County.90 At some point between 1744 and 1746 he obtained additional land as he sold his brother Isaac 320 acres in Feb 1746.91 The transaction where the 320 acres were obtained has not been identified, it is known only from the Feb 1746 deed. It is possible that the land came via a Crown patent as there is no record of it in the Granville Grants which are thought to be fairly complete.
Any land transactions after the 1740s involving Thomas (and for that matter his brother Isaac) are difficult to assign. Ignoring any references to Thomas away from the Little Fishing Creek area (Thomas Charles Mathews was on the northern border of the county which can further confuse matters) we run into the problem of knowing that there were multiple Thomas's and Isaac's in the area. Both brothers had sons named Thomas and Isaac.
Fortunately Thomas left a detailed will naming his wife and children. His wife is known from both the parish record of the christening of their son James (see above) and a single deed from Surry County dated 18 Sept 1744 where Thomas sold all 518 acres of his land in Virginia and his wife, Elizabeth, released dower.92 Thomas's will, written 15 Oct 1764, names his wife Elizabeth and 8 children.93 In the will several of his sons were noted as not being "of age" (meaning they had not reached the age of 21 at the time the will was written) giving us useful information to determine approximate ages. Additionally the will tells us who the three youngest sons are although there is no guarantee that they are named in order of age.
The names of the children were given, in order, as: Frances Coleman (married Robert Coleman), Charles, Sarah Hill (married Abner Hill), James, Milly, Isaac, Thomas and Benjamin. The will points out Thomas's youngest sons with the following statement: "...everything that is not already given I give to my three youngest sons, Thomas, Isaac and Benjamin to be equally divided among them." Note that the order in which Isaac and Thomas Jr. are named is reversed in the quoted statement from the way in which they appear earlier in the will. As seen in the section on Thomas Jr. a case can be made that he was born circa 1746 meaning Isaac was likely born a couple of years to either side of 1746.
Note that not much is known about Thomas Sr's children Sarah, Milly and Benjamin from my current research (although I believe Sarah's life can be fleshed out with further investigation). Sarah's husband, Abner Hill, was part of the Hill families that lived around the Matthews in Halifax County. They had at least one child, a daughter Frances. Later they moved to Chatham County, North Carolina with most of Sarah's brothers. Aside from her inclusion in Thomas Sr's will nothing is known of Milly. Nothing is known of Benjamin aside from his name appearing in his father's will and a single deed from Halifax County, North Carolina.
In 1774 he sells that land his father left him in Halifax County and the deed makes note of the fact that he lived in Chatham County at that time.94 After 1774 nothing more is known about him.