Osric Stark is remembered by the Night's Watch since he was chosen as Lord Commander of the Night's Watch at the age of 10. He was a close relative of a King in the North and served for 60 years.
In the books
In the A Song of Ice and Fire novels, Osric Stark was elected Lord Commander of the Night's Watch at age ten, four hundred years before the War of Conquest, though he ultimately served as Lord Commander for sixty years.
Samwell Tarly specifically brings up the example of Osric Stark to point out that in the centuries-long history of the Night's Watch, boys younger than Jon Snow (who is around 16 years old at that point) have been elected as Lord Commander of the Night's Watch.