Troides helena common in many of the localities in which it occurs, was classified as vulnerable in 1985. Helen in Greek mythology Helen was the daughter of Zeus. Cerberus or Kerberos, in Greek and Roman mythology, is a multi-headed hound which guards the gates of the Underworld. This species is protected under Wild Animals Protection Ordinance Cap 170 in Hong Kong. The common birdwing is protected in Indonesia and may also require protection in peninsular Malaya also. It is listed in Appendix II of Convention on the International Trade in Endangered Species of Wild Flora and Fauna (CITES) as are all other
Gate deities of the underworld only to the souls capable of pronouncing the secret name of the god himself, as a sort of "password". The walls of many Pharaonic tombs in the Valley of the Kings are decorated with the texts of the Book of Gates, which describes the twelve gates or pylons of the underworld: in spite of being imagined as architectural barriers to all intents and purposes, the gates were individually named as goddesses. Chapter 144 of the Book of the Dead mentions seven gates, each with its own God, a Doorkeeper and a Herald: for example, the 7th gate is guarded by