Joseph Henry of Straffen was the second son of Hugh Henry of Lodge Park, Straffan Co. Kildare, a Dublin merchant and banker and his wife Anne Leeson, sister of Joseph Leeson (1711-1783), 1st Earl of Milltown. Joseph Henry inherited the estate of Straffan in 1743 and was M.P. for Longford (1761-1768) then Kildare (1770-1776) and in 1771, High Sheriff of Kildare. His portrait of c.1751 by Pompeo Batoni is in the Walters Art Museum, Baltimore (37.1932).
Henry was a considerable connoisseur and patron, having already been portrayed as a young scholar by Francis Hayman c.1745 (Christie's London, 17 May 2001 (61). He was one of the most erudite Irishmen to make the Grand Tour in the mid-18th Century and was accompanied to Italy in 1750-51 by his uncle, Joseph Leeson and his cousin Joseph, later 2nd Earl of Milltown. They took a house in Rome near the Piazza di Spagna, becoming significant figures in the British and Irish community which centred on the Spanish Steps.
Henry commissioned a pair of views of Tivoli (P44 & P45) from Wilson and ordered four paintings from Vernet in May 1752. He was caricatured more than once by Pier Leone Ghezzi, e.g in a drawing in the Metropolitan Museum of Art, New York. He also commissioned the young Joshua Reynolds's most celebrated caricature, Parody of the School of Athens (National Gallery of Ireland, Dublin) appearing himself in the role of Diogenes the Cynic, sprawling on the steps. He was recorded in Spain and Pisa in the mid-1750s and met Robert Adam in 1755 and 1757 in Pisa and Florence respectively. He continued his Grand Tour after the departure of his uncle and cousin until 1761. Three years later he married Lady Catherine Rawdon, daughter of the 1st Earl of Moira. He maintained a house in Henry Street, Dublin, containing his art collection, where he died in 1796.
See further: J. McDonnell, 'Joseph Henry of Straffan: A Connoisseur of Italian Renaissance Painting', M. McCarthy ed., Lord Charlemont and his Circle, 2001, pp. 77-90.