Nothing is known for certain about the early life or family background of this Member, although he may have been related to the John Roxton, who, with his wife, Alice, and their son, John, obtained a settlement of the Bedfordshire manor of Wyboston at some point before 1358. Another John Roxton became head of the Augustinian priory of Dunstable (in the same county) during the late 1420s, but once again direct evidence of any connexion with the subject of this biography remains lacking.
Although he sat just once in the House of Commons, Roxton attended the county elections fairly regularly. He witnessed the return of shire knights to at least six Parliaments: namely those of 1425, 1426, 1427, 1433, 1435 and 1437. He was, meanwhile, one of the local gentry who were required, in May 1434, to take the general oath that they would not support persons breaking the peace. The name Thomas Roxton actually appears twice on this list of Bedfordshire landowners, perhaps as a result of an administrative oversight, but possibly because the MP had a son or kinsman of the same name. He was still alive in July 1443, the date of royal letters patent confirming him and his co-feoffees in possession of a sizeable estate in Bedfordshire which had been settled upon them in trust two years before by Thomas Woodhall. On the latter’s death the property had mistakenly been assigned to the Greys’ sworn enemy, John, Lord Fanhope, although Roxton and his associates were able to prove their superior title.
