Turner was employed by the physician Thomas Monro (1759 - 1833) to make copies of watercolours in his collection between 1794 and 1796. Monro was a keen supporter of the arts and engaged several young artists in this way. It helped them develop their drawing and watercolour skills.
This view of Lake Nemi in Italy is not a direct copy. It was probably based on several similar works by John Robert Cozens (1752 - 1797) in Monro’s collection. Turner had not yet travelled abroad at the time.