It's from the Dragonlance Legends trilogy. The books are set in one of the D&D universes, "Dragonlance", and focus on the story of twin brothers (Raistlin and Caramon Majere).

An important part of the plot is the love story between Raistlin, "evil" wizard, and Crysania, "good" priestess. I won't tell more so you're not spoiled if you ever read it - wich I encourage you to do : the books may be old (published in 1986) but they are still good classics of sword and sorcery.