Late 16th century; earliest use found in Thomas Nashe (d. c1601), writer. From post-classical Latin prorex viceroy, governor of a country from classical Latin prō- + rēx king.
Definition of prorex in US English:
prorex
nounˈprəʊˌrɛks
historical
A deputy king; a viceroy.
Origin
Late 16th century; earliest use found in Thomas Nashe (d. c1601), writer. From post-classical Latin prorex viceroy, governor of a country from classical Latin prō- + rēx king.