In 1819 Gibson "began a large group, 'Mars and Cupid' (marble, 1825; Chatsworth, Derbyshire) and, while modelling it, received a visit from William Spencer Cavendish, 6th duke of Devonshire. The duke, one of the leading collectors of modern sculpture in Rome, had been sent by
Canova, and he ordered the work in marble. Though Gibson claimed to have undercharged for the work - 'I did not make even a cup of coffee by it', he remarked - nevertheless the commission effectively launched his reputation in Rome, and in the following years he enjoyed the patronage of some of the leading collectors of the day [DNB]."
Congratulating Gibson on the arrival of a fine block of marble from Carrara. Devonshire gives him permission to draw £100 as part of his payment.