A person's’s identity is so important within the world of Le Morte d’Arthur. Each character is defined not only by his familial relations, but also by his abilities, whether on the battlefield, as a lover, or as a leader. A person is also defined by his loyalties to his country or liege. Knights are usually defined with epithets about their abilities or loyalties, sometimes given through fate, sometimes through their own accomplishments. Many people struggle with identities given to them by fate or circumstance. For instance, when Arthur was young, he thought of himself as the adopted son of a landowner and knight, not as the heir to all of England. After Arthur learns he is the son of Uther Pendragon and Igraine, he has a hard time accepting his identity, even though that identity compels him to take power meant for him by fate. Similarly, his son Mordred also has difficulty accepting his identity - though he is predestined to kill his father, he is bothered by the Archbishop of Canterbury's statements on his sinful conception.
Interestingly, though, many characters often don disguises. For instance, Sir Launcelot frequently hides his identity so that he can solicit jousts with knights who might otherwise be too frightened to fight him. Mistaken identity in Le Morte d’Arthur often results in tragedy, as was the case for the brothers Balin and Balan. Merlin is perhaps the most persistent in his attempt to conceal his identity, mostly from Arthur, as he transforms into old men or young children, usually to teach the King a lesson. The regularity of disguise suggests that characters often wish freedom from an identity that otherwise too fully limits them in the eyes of others.
Destiny
Several characters within Le Morte d’Arthur are predestined to certain ends. Some examples include: Arthur was meant to bring peace to a fractured country; Mordred was meant to destroy his father’s kingdom; and Galahad was destined to find the Sangreal. The whole epic has a sense of inevitable fate because of its title, which foreshadows Arthur's death long before it happens. This makes sense, considering that Merlin prophesies it so early. Many of Merlin's prophecies are quite complicated; for instance, he sets Galahad up to be the world's greatest knights in several different ways. Whether a character's identity is determined by fate, or whether his character enables his fate, is a question only implicitly posed in the epic, but the supernatural forces that control the world are very explicit throughout.
The Journey/The Quest
The most repetitive theme in the text is that of the journey, or quest. Knights within Le Morte d’Arthur have a strong desire to seek adventure, to do noble deeds, and to find glory within the most difficult of circumstances. They undertake journeys for the sake of the journey alone, and not always for a specified goal (as is the case with the Sangreal). The desire to find adventures is sometimes all-consuming; for instance, King Pellinore is so intent on his quest that he ignores a young woman's pleas for help. The existence of the Questing Beast suggests the importance of a quest - even if it seems impossible, a knight will continue to pursue it. The most prestigious quest is certainly that for the Sangreal, which has both a physical and spiritual component, suggesting that after the age of Arthur, people will need to journey inwards into themselves to find purity, and not simply outwards to find fame. Even the task of reading Le Morte d’Arthur is a journey in itself, as we travel with the characters from one adventure to the next.

Love
Variations of love exist within Le Morte d’Arthur. The most immediate is that which the Knights of the Round Table have for Arthur, a love that helps the fellowship stay strong. There is also the love of God, which inspired the Knights to attempt the difficult task of finding the Sangreal. Love of family is prevalent, whether characters were defending or avenging family members.