I just finished reading Robert Anton Wilson's COINCIDANCE, which includes four essays on James Joyce and articles on various other topics. Reading it made me realize that the protagonist's name in ILLUMINATUS! apparently contains a James Joyce reference.
You could argue that ILLUMINATUS! does not have a protagonist, as it shifts in viewpoint to many different characters. The two main characters who are used to transmit the author's viewpoints, however, are Hagbard Celine and Simon Moon, and of those two, it's my impression after reading the work several times that Celine is the most important character in the book.
With me so far?
Wilson, a longtime James Joyce fan, writes in COINCIDANCE about HCE, the protagonist of FINNEGANS WAKE, which Wilson called his favorite book.
Now look at Hagbard Celine's name: Hagbard CelinE.