The book indicates that it takes place in the midst of an unspecified nuclear war. Some of the marooned characters are ordinary students, while others arrive as a musical choir under an established leader. Most (with the exception of the choirboys) appear never to have encountered one another before. The book portrays their descent into savagery; left to themselves in a paradisiacal country, far from modern civilisation, the well-educated children regress to a primitive state.
At an allegorical level, the central theme is the conflicting human impulses toward civilization—living by rules, peacefully and in harmony—and toward the will to power. Themes include the tension between groupthink and individuality, between rational and emotional reactions, and between morality and immorality. How these play out, and how different people feel the influences of these, form a major subtext of Lord of the Flies. The name "Lord of the Flies" is a literal translation of Beelzebub, from 2 Kings 1:2-3, 6, 16.