Why does the author give the title "Lord of the Flies"?

Lord of the Flies refers to the devil, also known as Beelzebub. As the novel progresses, the children lose their sense of civility. They become dirty (The Lord of the Flies is also called the Lord of Filth and Dung), both inside and out. As Jack's group reverts to savagery, they look for a symbol and embrace the Lord of the Flies as a god. The pig's head, which is used as an offering and impaled on a steak, is eventually devoured by flies and becomes a symbol. In response, Ralph seizes the stake at the end of the novel to use as a spear and knocks the pig's skull to the ground. It's the fight between good and evil (civility as opposed to savagery).