Thomas Jones (1742-1803), landscape painter, was born in the parish of Cefnllys, Radnorshire, but is usually associated with the mansion of Pencerrig, Llanelwedd, in the same county, where he was brought up. Intended by his parents to take Holy Orders, he was educated at Jesus College, Oxford, but left in 1761 to devote himself to painting. He went to London, initially to train under Shipley at the Royal Academy, and finally with the renowned Welsh painter Richard Wilson.

His career progressed successfully for ten years, during which time he painted mainly landscapes - including several of the landscape around Pencerrig.

In 1776, Thomas Jones went to Italy and the paintings he produced in Rome and Naples, of buildings which were in view from his residence, have now become recognised as outstandingly original, being a century ahead of their time. Thomas Jones had a great influence on such painters as Corot and thus on the French Impressionists. Indeed, he is now recognised by art historians as being of major importance in the development of the European art tradition.

In 1783 he returned to Britain and exhibited regularly at the Royal Academy. When his elder brother died, Thomas inherited Pencerrig, where he lived with his Danish wife and two daughters until he died in 1803.