Complex sentence: In the first book he is backstabbed by Briar Cudgeon, someone he grew up with since childhood-however, Cudgeon botched his attempt to remain commander in the first Artemis Fowl book and Root was quickly reinstated.
Split into simpler sentences: In the first book he is backstabbed by Briar Cudgeon, someone he grew up with since childhood. However, Cudgeon botched his attempt to remain commander in the first Artemis Fowl book and Root was quickly reinstated.