1690s in reference to the government by the Cromwells; 1795 as "occupied territory of another nation," from protector + -ate (1). Meaning "state or territory (usually tribal) placed under the protection of a major power" is from 1860.
protection
protectionism
protectionist
protective
protector
protectorate
protege
protein
proteinuria
protero-
Proterozoic