What is "seti-merenptah"

Seti-Merenptah was an ancient Egyptian prince of the late 19th dynasty, a son of Pharaoh Seti II.

He is depicted behind his father in Seti's small Karnak temple. His figure replaces another, probably that of Chancellor Bay. It is assumed that he was born in the last year of his father's reign and died in Siptah's fourth year, but it's not proven.