When the story's protagonist finds a sword and avidly learns swordplay, we should suspect a hero's tale. Certainly, there are elements of this Romance that demonstrate ethical qualities that are being heralded by the writer as noble and honorable. That means that it is a book of "Romance" in two senses that are related but different: There is the elaboration of a young man's journey toward a life of honor (as in "Bildungsroman," emphasis on "-roman"), and there is the story of his discover of love.
These two are tangled amongst one another in an exchange the reader might properly call "Chivalry." That doesn't mean he just opens the door for women at the shopping mall: It is an entire religious code that the hero accepts as a kind of standard for his behavior and opinions. In other words, he is challenged and tasked to learn self-control and responsibility, at the same time learning the difficult truth that life is often more painful than expected.
Iseult and Tristan are in love, but he marries someone else and spies on his true love from two roles: the madman and the leper. These are instances of two alternative stories that could have played out, he identifies as a madman toward his beloved because he is struggling to understand the mythic nature of romantic disappointment. It makes him struggle with self-worth. Then the leper is an reminder of health. Perhaps these are Tristan's imaginary ways of saying, "If I could be with my lover, I'd feel sane and healthy." Ultimately, death is their reunion, and death is also the answer to Tristan's Bildungsroman. As the saying goes, "Memento mori."
