[1] By licence dated 18 July 1689 he married Alice Proby, a daughter and heiress[2] of Sir Thomas Proby, 1st Baronet,[3] by whom he had children including: In 1695 Watson inherited the fortune of his maternal uncle William Wentworth, 2nd Earl of Strafford, including the vast estate of Wentworth Woodhouse in Yorkshire, with others in Northamptonshire and Ireland.
In accordance with the terms of the bequest,[4] Watson adopted the additional surname of Wentworth, becoming Thomas Watson-Wentworth.
However his opponent died within a year and Watson-Wentworth was returned unopposed for Higham Ferrers at a by-election on 22 November 1703.
He made little impression in his first parliaments, but being a church supporter moved progressively towards the Tories culminating in opposing the impeachment of Henry Sacheverell and being considered a worthy patriot.
[5] Watson-Wentworth died at Harrowden on 6 October 1723 and was buried in York Minster where his elaborate monument with standing marble effigy survives.