The main theme of 'Lord of the Flies' is the conflict between civilization and savagery. The boys start off with some sense of order, but as time goes on, the savage nature within them takes over. Another theme is the loss of innocence. The boys, who were initially just schoolboys, become killers and lose their child - like purity.
It's not historical fiction. 'Lord of the Flies' is a work of fiction that delves into profound psychological and social concepts through a fictional scenario, not drawing from real historical occurrences.
'Lord of the Flies' is fiction. It's a novel that creates a fictional and allegorical story about a group of boys stranded on an island. The events, characters, and the entire island setting are products of the author's imagination.