Kushiel's dart

Kushiel's Dart is a fantasy novel by American writer Jacqueline Carey, the first book in her Kushiel's Legacy series. The idea for the book first came to Carey when she was reading the Biblical Book of Genesis, specifically a passage about "Sons of God" coming into the "Daughters of Men". Later, when she was writing a coffee table book, she encountered Jewish folklore, which paralleled the story in greater detail. The fictional nation of Terre D'Ange in the story was founded by a rebel angel.