Cullum Gelderris is the tavern keeper of The Cracked Flagon. He briefly appears in The Sorcerer in the North and also in The Siege of Macindaw.

He is eager to talk and tells Will, who is travelling undercover as a jongleur, a lot about the situation up in Macindaw and how Syron was poisoned and his son, Orman doesn't do his job as the Lord of Macindaw as he should.

He appears also at the beginning of The Siege of Macindaw when Horace arrives also undercover, as a freelance knight. Cullum doesn't like the fact Horace is a little nosy and is uncomfortable that he is staying in the inn due to the fact it attracts some of the thugs Sir Keren has signed up as soldiers at Macindaw.