The novels blend science fiction, fantasy, and political intrigue, with some in the Vatican and the Empire striving for peace, and the Rosen Kreuz Order doing anything in its power to stop it.

At the start of the story, the Methuselah, still a major political and military force, continue to wage war on the "Terrans", as they call the human inhabitants of Earth.

A third great power, Albion also plays a role in the war with its superior arsenal of lost technology and weapons and higher level of manufacturing ability versus the Vatican.

The independent monarchy of Albion is a primarily human country, however the secret of their expertise in lost technology is found in the Ghetto, an underground city of enslaved Methuselah.

It is these Methuselah who operate and manufacture the lost technology, but with the death of the Albion Queen, some of the enslaved vampires begin a rebellion for the freedom of all of the Ghetto residents.

While the novels, manga, and anime series all cover the same basic story and feature many of the same characters, they do have some minor and major differences.

The anime series' introductory-style episodes are based on the novel segments with the same names, but they are told in a different story.

Nine hundred years later the surviving humans are still trying to recover from the war's devastating effects while trying to find ways to co-exist with the Methuselah despite the distrust and hatred still evident on both sides.

The Vatican serves as the primary leader for the people in the ongoing struggle for peace with the Methuselah, and in dealing with rogue factions from both sides that would like the war to continue.

[8] Whereas the Methuselahs are either born or infected, the Crusniks are unique beings created as a result of an experiment during the Mars Colonization Project.

The three Crusniks, Seth, Abel, and Lilith, were test tube babies created for the Mars Colonization Project by the UNASF with genetically enhanced bodies.

In order to activate his Crusnik powers, Abel usually issues a verbal or mental command to the nanomachines in his body.

The exact wording and method of activation varies among the novels, the manga, and anime, and between the original Japanese and the English translations.

[9] In the anime, neither Cain nor Seth demonstrated a need to do this in order to activate their powers, and there are several times when Abel activates his powers without saying his usual command, so it appears to just be a literary device; the only exception to this is in the third novel where Sister Paula Souwauski, who is in combat with him, prevents the change by not letting him finish the statement, as it would flip the playing field as Abel in his human form is ranked as having a B− fighting ability while his 40% Crusnik is described as an S+.

Written by Sunao Yoshida and illustrated by Thores Shibamoto, Trinity Blood consists of two six-volume sub-series.

[10][11] Following the novels, a book containing backstory, world information and unreleased stories entitled Canon Summa Theologica, was released May 1, 2005.

[30] The chapters of the Trinity Blood manga series are illustrated by Kiyo Kyūjō, with story assistance by Kentaro Yasui.

[4] The series premiered in the shōjo manga magazine Monthly Asuka in 2004,[4][11] and finished in April 2018,[10] after transferring to Comic Newtype website in 2016.

In Australia and New Zealand, both the Chuang Yi and Tokyopop volumes are being released by Madman Entertainment through an importation agreement.

[citation needed] The Trinity Blood anime television series premiered on the satellite network Wowow on April 28 and ran through October 6, 2005, spanning a total of 24 episodes.

[57] The series also aired in Malaysia on ntv7, in Australia on the Australian Cartoon Network's Adult Swim, and in Spain on Buzz Channel.

[62] The first volume of the Trinity Blood manga reached the 30th spot on the Top 100 Graphic Novel sales for November 2006.

[64][65][66] The Trinity Blood anime series enjoyed strong television ratings when it originally aired in Japan.