He was the fourth son of Edward Weld and Dame Mary Teresa, née Vaughan of the Welsh Bicknor exclave in Herefordshire.
[6] He was reputedly not a distinguished scholar, due to repeated disruptions of his schooling from local political turmoil, but he developed an attachment to the community he met there and it fostered his lasting interest in education.
Edward had not yet signed a new will reflecting his marriage, and the entire family inheritance fell to Thomas, who did not provide any support for his sister-in-law, forcing her to promptly remarry.
She was introduced to the Prince of Wales, the future George IV and they contracted a morganatic marriage in 1785, which was repudiated both by the king and the Privy Council of England.
It is said the most sumptuous was the library indicating he was a keen bibliophile who possessed a number of exceptional rarities in his collection, including the Luttrell Psalter, and Shakespeare's history textbook, Holinshed's Chronicles 1587 2nd edition.
He was a friend of another Jesuit school alumnus, Giles Hussey (1710-1788), a Dorset artist specialising in portraiture and depictions of Charles Edward Stuart.
[1] Although the "Castle", originally intended as a hunting lodge, fell victim to a disastrous fire in 1929, a number of valuable items it housed appear to have been saved.
Unless it had been sold prior to the fire, one of them would have been Engelbert Kaempfer's History of Japan, translated from the German manuscript held by Sir Hans Sloane and published in 1728.
[13] In the absence of public catholic worship, the Welds were accustomed to having services celebrated by a personal chaplain in a chapel space within the castle.
He was a French ordained Jesuit priest, named Jean Grou, who as well as fulfilling his pastoral duties, was a prolific writer on spiritual matters.
[14] Owing to his personal friendship with King George III, Thomas Weld was able in 1786 to build a Roman Catholic church dedicated to St. Mary to serve as the family chapel in the grounds of Lulworth Castle.
He asked John Tasker who was responsible for the interior refurbishment of the castle, to design it drawing inspiration from a classical Greek mausoleum, at a cost of £2,380.