Marshal of the Mark was the highest military rank within the Rohirrim, and the title of the King of Rohan’s Lieutenants. There were typically three Marshals of the Mark and they were commanders of the royal forces of fully trained and equipped Riders.

The titles and charges of the three Marshals were as follows:
- First Marshal of the Mark : the King's Lands
- Second Marshal of the Mark : the West-mark
- Third Marshal of the Mark : the East-mark

In times of war, each Marshal had, under his immediate orders, as part of his household (which meant those quartered under arms at his residence), an éored ready for battle which he could use in times of emergency at his own discretion. He could then call a Muster of his people to ride forth immediately.