Thomas Richard Underwood was born at 43 Lamb's Conduit Street, where his father, also Thomas Underwood, lived until 1808. The younger Underwood was a watercolourist and later a geologist; he exhibited at the Royal Academy often between 1789 and 1802. In 1800 he became a proprietor of the Royal Institution and was instrumental the following year (the same year as Hays's letter) in procuring the appointment of Humphry Davy as assistant lecturer. Underwood was already known to S. T. Coleridge, Southey, Wordsworth by 1801, and most likely Hays came to know him through her literary contacts as well, probably the Fenwicks and their friend, Charles Lamb. Underwood traveled to Paris with Thomas Wedgwood in 1803 and was detained upon his departure until 1814, when he was allowed to return to England.