Just as Joyce modeled Mulligan on his friend Gogarty, he modeled "Haines" on Gogarty’s other guest in the tower, a well-born young Englishman named Richard Samuel Chenevix Trench (1881-1909). Gogarty met Trench during a term at Oxford in early 1904, a fact which accounts for Mulligan's referring to "the oxy chap downstairs." Haine is French for “hate.” 

JH 2011

Poster for La Haine, French black-and-white film by Mathieu Kassovitz (1995).

Copy of Dermot Trench's What is the Use of Reviving Irish? (1907), held in the James Joyce Museum, Sandymount. Source: John Hunt.