Roch, Sampson Towgood (1757–1847), miniaturist, was eldest son of William Roch and Melian Roch (née Holmes) of Youghal, Co. Cork; grandson of James Roch of Glyn Castle, near Carrick-on-Suir, Co. Tipperary; and great-grandson of James Roch, high sheriff of Co. Waterford. On a visit (1773) to his kinsmen in Cashel, Co. Tipperary, he first showed indications of a talent for drawing, making some sketches of scenery and endeavouring to execute small likenesses of his family and friends. There is no evidence to show that Roch had any formal training as an artist, and Pasquin states that he was self-taught. It is likely that he was familiar with artists working in Cork, where he was in 1787. During this early period Roch painted several family portraits. The earliest surviving dated works are portraits of his father (1777) and his mother (1781) (private collection).
By 1779 he had taken up residence in Dublin, in the parish of St John. His name does not appear as a student at the Dublin Society schools, nor is he known to have been apprenticed to any of the established painters of the time. Established in Dublin by 1782, Roch had already travelled to England, since a signed and dated portrait exists, painted by him in that year, of Mrs Thrale, friend of Samuel Johnson. Roch had returned to Dublin by 1784, for his name appears as a miniature painter resident at 152 Capel St. in that year. By this stage Roch must have come under the influence of Horace Hone (qv), who also lived in Capel St. Hone came to Ireland in 1782 and painted a portrait of Roch (1785). Roch did a copy of Hone's miniature portrait of Lord Charlemont (qv) in 1786. In 1786 he left Dublin to work in Cork, where he was living when his family arranged his marriage to his first cousin. The bride, who brought a handsome dowry, was Melian Roch, only daughter of his uncle James Roch and James's first wife, Isabella Odell of Odell Lodge, Ardmore, Co. Waterford. They were married 29 May 1787. Roch returned to Dublin in 1788 and lived (1789–92) in Grafton St. There he painted prosperous country people and the Dublin middle classes in such portraits as those of Mrs Mangan and Mrs Thorp (both in the NGI).
Roch left Dublin in 1792 and took up residence in Bath, where he remained until 1822, working there successfully as a miniaturist. Bath had become a fashionable resort after the discovery of the Roman baths there in 1755. The aristocracy and upper classes provided the miniaturists with the sort of patronage they required. Roch, in order to avail himself of this opportunity, had made an earlier visit to England before actually settling in Bath. While at Bath, he won valuable commissions from the aristocracy and royalty, including a portrait of the youngest daughter of George III, Princess Amelia (private collection). Such a commission helped Roch to establish his reputation. He painted several members of the royal family and is said to have been offered a knighthood, an honour he declined on account of his infirmity (he was deaf and dumb from birth).
The amusements at Bath were presided over by two masters of ceremonies (one for the upper rooms and one for the lower), elected to that office by the subscribers to the assemblies and balls. Roch painted the portraits of two of the most renowned masters of ceremonies, Charles Le Bas and James King (both in the Victoria Art Gallery, Bath). The naval and military services were valuable sources for commissions, and a Roch portrait of Adm. Fellowes (private collection) and several portraits of unknown officers survive from this period. One of his most interesting sitters was the aforementioned Hester Thrale (née Lynch; later Mrs Piozzi) (1741–1821). Roch's 1782 miniature of her may have been painted as a dissuasive memento to Dr Johnson, who wanted to marry her (a widow) at this time, but whom she wanted to shake off; alternatively it might have been painted as an intimate token for Gabriel Piozzi, whom she wished to marry. Mrs Thrale went to Bath in 1793 as a result of family pressure and public disapproval of her wish to marry Piozzi. Later she divided her time between London and Brighton, and it was probably in the latter location that Roch painted her a second time in 1816. She gave this portrait to a Mr Maginn in 1818 as a gift in a special case, containing lines of her own composition; a good example of the keepsake nature of miniature portraits.
The final period of Roch's career covers his return to Ireland (1822) and subsequent retirement, during which he continued to paint portraits and sketch local life. He probably worked in Cork for a time and eventually went to live with his family at Woodbine Hill, Co. Waterford. His wife died 21 September 1837. Ten years later he died and was buried at the family plot at Ardmore, Co. Waterford, on 20 February 1847.
Roch's work is characterised by the excellence of his technique, which varied little throughout his long career; he handled detail such as jewellery, hair, costume, with a minuteness of brushstrokes of superb quality. A distinguishing feature of his portraits is that so many of the sitters are painted with an incipient smile and sometimes even an actual grin. Some critics have considered this a defect, but it often conveys something of the character or rakishness of the sitter. A less obvious detail, characteristic of Roch's style, is his frequent use of light shading around the sitter's eyes.