Complex sentence: Trisiras is beheaded by Hanuman, the monkey-companion "Lanka kanda", this book describes the Ramayana War between the army of Rama and the army of Ravana.
Split into simpler sentences: Trisiras is beheaded by Hanuman, the monkey-companion of Rama. Also known as "Lanka kanda", this book describes the Ramayana War between the army of Rama and the army of Ravana.