satrap

satrap \SEY-trap\, noun:

1. a subordinate ruler, often a despotic one.
2. a governor of a province under the ancient Persian monarchy.

I govern this land for my brother, and as his satrap it is my duty to know much of the neighboring lands.

-- Gene Wolfe, Soldier of Sidon

It was common knowledge: this baby's father was some sort of latter-day satrap, a king of the East who had fetched himself a blond, horse-toothed bride from a women's college in New Jersey.

-- Chris Adrian, The Children's Hospital

A Medieval word, satrap originated in the Old Persian from the literary prefix kshathrapavan-, meaning "guardian of the realm."