Marq Rankenfell

"Tristan Mudd, Mad Marq Rankenfell, Robin Hill. Each nearly destroyed us with their foolishness."

- Ser Alliser Thorne

Marq Rankenfell is an unseen character. He is not expected to appear in the show, being long dead by the time it begins. He's known to history as Mad Marq Rankenfell

Biography
Marq Rankenfell at some point he joined the Night's Watch, and eventually rose to become its Lord Commander. The Watch nearly collapsed under his leadership, and history remembers him as one of the worst Lord Commanders the Black Brothers ever had - along with the likes of Tristan Mudd and Robin Hill - and is remembered as "Mad Marq Rankenfell".

In the books
In the A Song of Ice and Fire novels, Marq Rankenfell's history is the same.