Percy Jackson and The Lightning Thief is a 2005 American children's fantasy action-adventure middle grade children's fiction novel based on Greek mythology written by American author Rick Riordan. The first children's novel by Riordan and the opening installment in Percy Jackson & the Olympians series, the book was recognized among the year's best for children. Riordan followed the novel with various books and spin-off series, spawning the Camp Half-Blood Chronicles media franchise.