Pars was sent to Rome on a bursary by the Society of Dilettanti in 1775; he remained in Italy until his death from pleurisy seven years later. Although he had been a portrait painter from the start of his career, and remained one, he is now known almost exclusively for his work as a landscape watercolourist. In Italy he associated with the large group of English artists working in Rome, notably John 'Warwick' Smith, Francis Towne and Thomas Jones. This watercolour was a preliminary study for a more highly finished version made for sale to a patron. The Colosseum had been consecrated in 1750 as a memorial to the early Christians martyred there, and a chapel and Stations of the Cross erected round the interior.