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
In the Courts of the Crimson Kings will proceed to the next stage. Though both are unsure what this means, but they soon discover that three interplanetary "Gates" have opened up on Earth, Venus and Mars, each leading to another world. The book ends with Teyud and Jeremy visiting "Vow'da" (Moon-World) the new world on the other side of the Martian gate. "Publishers Weekly" called it "charming", and praised Stirling for "successfully creat[ing] a truly alien environment", but criticized his "inclusion of pirates with eye patches, heavily armored guards riding 'fat-tired, self-propelled unicycles' and other moments of near-parody." "Kirkus Reviews" lauded Stirling's "magnificently wacky Martian biological machines"