This print, 'Fifth Plague of Egypt', is plate 16 of Turner's 'Liber Studiorum' series. It is an example of the 'Historical' category of landscape painting. It was published with the 3rd part of the series on 10 June 1808.
The 'Liber Studiorum' illustrated Turner’s arguments for the supremacy of landscape painting. The title means ‘book of studies’ in Latin. It contained no written text, instead it was made up of individual mezzotint prints on paper. They were released in fourteen parts from around 1807 until 1819. Turner intended the 'Liber' to consist of 100 prints but only 71 were ultimately produced.
The prints reflected the five categories of landscape painting Turner believed existed: architectural, historical, marine, mountainous and pastoral. Turner wrote an initial on each work to indicate which category it belonged to.