Black Trillium is a 1990 Fantasy novel co-written by Andre Norton, Marion Zimmer Bradley, and Julian May. It is also the first book in the Trillium series, consisting of four more novels set in the same universe and featuring more or less the same cast. After the original novel, however, the three co-authors decided to write the sequels separately, so there are effectively three mutually exclusive continuities, of which Black Trillium is the lowest (and only) denominator.
- Black Trillium (1990). The original novel begins with the evil kingdom of Labornok conquering the neighboring kingdom of Ruwenda. The only remnant of the Ruwendan royal family are the young triplet princesses, who are rescued by their servants and smuggled across the conquered country to the White Lady, who was supposed to protect Ruwenda from the invasion. From there on, the three princesses must brave three different paths to retrieve three parts of the mightiest weapon left behind by The Precursors, the Scepter of Power.
- Blood Trillium (1992, May).
- Golden Trillium (1993, Norton). Some time after the conclusion of BT, Kadiya, the second princess, leads an expedition into the Thorny Hell to uncover a few of the Ancient's secrets.
- Lady of the Trillium (1995, Zimmer Bradley). 900 years after the BT, Haramis, the oldest princess and the current White Lady, is faced with the challenge of selecting and educating a successor for herself.
- Sky Trillium (1997, May).
The principle characters of the novels are:
- Haramis, the oldest of the three princesses. A bookworm since childhood, she is the most intelligent of the three and her mastery of magic soon surpasses pretty much everyone in the world. Her personal artifact is the Three Winged Circle (a wand) and since the end of BT, she is known as the White Lady and the Arch-Sorceress of the Land. In the original novel, her chapters were written by Marion Zimmer Bradley.
- Kadiya, the second princess, is a Lady of War and has a brash, passionate personality, often putting her at odds with the logical Haramis (especially in May's continuity). Her personal artifact is the Three Lobed Burning Eye (a sword) and after BT, she is known as the Lady of the Sacred Eyes, serving as the protector of the Oddlings. In the original novel, her chapters were written by Andre Norton.
- Anigel, the youngest princess. A Princess Classic who mediates the other two and seeks diplomatic solutions. Her personal artifact is the Three Headed Monster (a crown) and after BT, she succeeds her father as a queen of Ruwenda, immediately marrying Antar, the prince of Labornok, and uniting the two kingdoms into Laboruwenda. In the original novel, her chapters were written by Julian May.
- Orogastus, alias Portolanus. The Evil Sorcerer who was really behind Labornok's aggression and an on-and-off love interest for Haramis. His role and motivation are greatly expanded in May's continuity.
- Antar, the Crown Prince of Labornok. The Wise Prince who mistrusts Orogastus and later defects to Anigel's army and eventually marries her. In May's continuity he often plays the Damsel in Distress role for Anigel.
Tropes used in Black Trillium include:
- Alternate Timeline: The original novel is the only one whose plot canonically happens in all three continuities, although Norton and Zimmer Bradley's continuities don't contradict each other (since they only concern their respective heroine and are chronologically 900 years apart).
- Badass Bookworm: Haramis, after learning magic.
- Damsel in Distress: Surprisingly, it is Antar who often causes trouble to his frail princess wife Anigel.
- Dating Catwoman: Haramis and Orogastus have... an uneasy relationship. Although in the end of Sky Trillium, they seem to finally get together, after Orogastus settles down as the Arch-Wizard of the Sky.
- Dismantled MacGuffin: The Scepter of Power.
- The Empire: Labornok is a militaristic, expansionist human kingdom.
- Everything's Better with Princesses
- Evil Sorcerer: Orogastus, who becomes an Anti-Villain in May's continuity.
- The Federation: Ruwenda is an aging kingdom that unites both humans and oddlings, and the only reason why it wasn't conquered for so long was White Lady's protection.
- Freudian Trio: The three princesses. Let's see...
- Beauty, Brains, and Brawn: Anigel, Haramis, and Kadiya, respectively.
- Blonde, Brunette, Redhead: Ditto.
- Freudian Trio: Haramis = The Spock, Kadiya = The McCoy, Anigel = The Kirk.
- Lady of War: Kadiya is the warrior princess.
- The Man Behind the Man: Orogastus manipulated the King of Labornok to declare war.
- The Obi-Wan: White Lady Binah.
- Princess Classic: Anigel.
- Round Robin: How the original novel was written.
- Royal Blood: All main characters except Orogastus are royals.
- Rule of Three: The series runneth over with it, especially May's continuity.
- Swamps Are Evil: The Thorny Hell is probably the single nastiest place on the planet.
- Time Skip: Lady of the Trillium fast forwards the narration 900 years into the future, when Haramis realizes that she will soon die of old age.
- The Wise Prince: Antar, whose Heel Face Turn was foreseeable from the moment his was introduced.