Trivia

The title "Trinity Blood" obviously alludes to the three blood strains featured in the series: Terrans (humans), Methuselahs (vampires) and Crusniks (über-vampires).

However, it also hints at the three Crusniks holding positions in different associations: Abel Nightroad - the Vatican (AX division); Cain Nightroad - the Rosenkreuz Orden; and Seth Nightroad - the Methuselah Empire.

Finally, it refers to the three major kingdoms in the series: the Vatican, the Methuselah Empire and the Kingdom of Albion.

The race of vampires is known as Methuselahs. In the Bible, Methuselah was famous for his long life (he lived to be 969 years old); this alludes to the vampires' longevity.

Three empires exist in the series: the Vatican, the Methuselah Empire and the Kingdom of Albion.

The Vatican has Rome as its capital and is primarily Catholic-Christian. Its rival, the Methuselah Empire, has its capital in Byzantium and possesses a distinctly Eastern culture (this holds a parallel with the historic clash between the Christians and the Muslims).

The Kingdom of Albion, with its mix of Terran and Methuselah, is a futuristic version of the United Kingdom (Albion is another name for Great Britain).

Abel Nightroad works in the AX Agency; AX is short for "Arcanum Cella Ex Dono Dei." This is Latin for "Papal State Affairs Special Operations Section."

The Rosenkreuz Orden (literally translated as "Order of the Rose Cross" ) is an actual organization founded by Christian Rosenkreuz in the 19th century (but did not have any nefarious world-domination plans like in the series).