According to a journal in a private collection by Dr. Anthony Todd Thomson (1778–1849), written during a stay in Edinburgh in 1823, he described his friend Williams as "a native of Devonshire".
1781) from Como in Italy, who married Hugh's step sister, Maria Ruffini on 6 June 1807, 3 days after the death of her father.
Williams had been creating watercolour landscapes, probably from the early 1790's, often in the Scottish Highlands where he established viewpoints; e.g. the Three Sisters in Glencoe, that would be imitated by others.
But he travelled widely in the United Kingdom working in London, Wales and the Lakes District where he was a favourite with John and Jessie Harden, he the editor of the Caledonian Mercury, and they shared a passion for capturing the landscape in watercolour.
Williams exhibited View of Loch Tay, in Scotland at the Royal Academy in London in February 1800 and in 1807 he was a founding member of the Associated Artists there; exhibiting with a slightly exotic group drawn partly from the émigré community of which he was a member; J. Huet Villiers (1772–1813) who had arrived from the continent in 1801, Walter Henry Watts ARA (1781–1850) born in the East Indies, son of a naval captain and Alfred Chalon (1780–1860), son of a Huguenot refugee from Geneva.
An extended tour in Italy and Greece, from 1816–1818, was funded by the recently unseated Member of Parliament, William Douglas of Orchardton (d. 1821), a wealthy amateur artist, who also accompanied him.
In 1822 and 1826 Williams held an exhibition of watercolours, based on his tour, the latter in aid of the building of the National Monument on the Calton Hill by his friends, the architects C. R. Cockrell and W. H. Playfair.
Their grave lies in the eastern extension of the churchyard, appropriately below the towering portico of Thomas Hamilton's Greek Revival masterpiece, the Royal High School on the Calton Hill.
In 1802 an engraving after a painting by Williams of Hermitage Castle, Roxburghshire, was published in Kelso as the frontispiece to Sir Walter Scott's Minstrelsy of the Scottish Border.
In 1814, Williams published six large aquatints of Highland scenery and the following year he exhibited View of Glen Coe, Highlands of Scotland at the Royal Academy, London (possibly Glencoe from the West, National Gallery of Scotland, DNG 350); a work that broke with traditional techniques and opted instead for a broad handling of watercolour washes in the manner of Peter de Wint.
His Travels in Italy, Greece and the Ionian Islands, from letters written to his friend, the artist John Thomson of Duddingston, appeared in two volumes in 1820.
Robina and the other trustees, Aeneas MacBean WS, and the miniaturist painter William John Thomson RSA, arranged a studio sale in 1831.