As nouns the difference between duchy and earldom
is that duchy
is a dominion or region ruled by a duke or duchess while earldom
is the rank of being an earl.
A dominion or region ruled by a duke or duchess.
* A Grand Duchy may be a self-governing state.
* A simple duchy tends to be a part of a larger kingdom or empire.
the rank of being an earl
* 1592, William Shakespeare, King Richard III
The territory controlled by an earl
- And, look when I am king, claim thou of me / The earldom of Hereford, and all the movables / Whereof the king my brother was possess'd.