Although there is scholarly debate regarding the origins of the personified river god, it is agreed that the variety of forms seen in the earliest representations were consolidated in the Hellenistic period. The god is typically represented as a muscular, mature man with luxuriant hair and beard as seen here, and he may also hold an attribute which identifies him as the god of a specific river.
The present bust closely follows a celebrated monumental full-length marble representing the river Nile which was excavated in the early 16th century near Sta Maria Sopra Minerva, Rome, along with a pendant figure of the Tiber (Vatican Museums, Rome and Louvre, Paris, respectively). In the 17th century those marbles were both in Rome and they were copied in a variety of media including bronze (for a discussion of the examples in the Wallace Collection see Wenley, loc. cit.). The original antique figure leans on his proper left elbow and extends his right arm along the length of his body, creating a slight distortion to the torso evident in the present marble bust.