Turner’s earliest history paintings followed the example of the Welsh artist Richard Wilson (1713-82). This picture is loosely based on an engraving of one of Wilson’s views of Lake Nemi in the collection of Turner’s patron, Sir Richard Colt Hoare, at Stourhead in Wiltshire.
Located south-east of Rome, Lake Nemi occupies a volcanic crater and was known as the mirror of Diana. This standard association led Wilson (and subsequently Turner) to add an incident from the myth of Diana to the foreground. Here she has just discovered the pregnancy of Callisto, one of her nymphs, whose tainted purity results in her banishment.