Julian May grew up in Elmwood Park, Illinois, a suburb of Chicago, the oldest of four children. Her parents were Matthew M. May (originally Majewski) and Julia Feilen May; as a child she was known as Judy May. She became involved in science fiction fandom in her late teens, publishing the fanzine Interim Newsletter for a time. She sold her first professional fiction, a short story called "Dune Roller", in 1950 to John W. Campbell's Astounding Science Fiction; it appeared in 1951 accompanied by her original illustrations. She met her future husband, Ted Dikty, later that year at a convention in Ohio. May chaired the Tenth World Science Fiction Convention in Chicago in 1952, and married Dikty in January, 1953. After selling one more short story, "Star of Wonder" (to Thrilling Wonder Stories in 1953), she dropped out of the science fiction field. May and Dikty had three children, the last of which was born in 1958.
Starting in 1954, May wrote thousands of science encyclopedia articles for Consolidated Book Publishers; after finishing that project, she wrote similar articles for two other encyclopedia publishers. In 1957 she and her husband founded a production and editorial service for small publishers, Publication Associates; the most notable projects May wrote and edited during this period include two episodes of the Buck Rogers comic strip and a new Catholic catechism for Franciscan Herald Press, a publisher associated with the Order of Friars Minor. Between 1956 and 1981 she wrote more than 250 books for children and young adults, most non-fiction, under her own name and a variety of pseudonyms; the subjects included science, history, and short biographies of modern-day celebrities such as athletes and musical groups.
Her story "The Dune Rollers", published under the name "Judy Dikty", was filmed in 1972 as The Cremators. 
Having moved to Oregon in the early 1970s, May began to get reacquainted with the world of fandom; in 1976, she attended Westercon 29 in Los Angeles, her first science-fiction convention in many years. She made an elaborate diamond-crusted "space suit" for the convention's costume party, which started her thinking about what sort of character would wear such a suit. She soon began accumulating a folder of ideas for what would become the Galactic Milieu Series, and in 1978 she began writing what would become the Saga of Pliocene Exile. The first book in that series, The Many-Colored Land, was published in 1981 by Houghton Mifflin. In 1987, she continued the series with Intervention, finally followed in 1992 (with a change in publisher) by the Galactic Milieu Series: Jack the Bodiless, Diamond Mask and Magnificat.
Bibliography of Adult Fiction (U.S. First Editions Only)more �� less
The Saga of Pliocene Exile
The Many-Colored Land (Boston: Houghton Mifflin, 1981). ISBN 0-395-30230-7.
The Golden Torc (Boston: Houghton Mifflin, 1982). ISBN 0-395-31261-2.
The Nonborn King (Boston: Houghton Mifflin, 1983). ISBN 0-395-32211-1.
The Adversary (Boston: Houghton Mifflin, 1984). ISBN 0-395-34410-7.
The Galactic Milieu Series
Intervention: A Root Tale to the Galactic Milieu and a Vinculum between it and The Saga of Pliocene Exile (Boston: Houghton Mifflin, 1987). ISBN 0-395-43782-2. (Released in the USA as two mass market paperbacks: Surveillance and Metaconcert. Released in the UK as a single volume)
Metaconcert (Intervention no. 2) Separate paperback. ISBN 0-345-35524-5 Publisher: Del Rey (January 13, 1989)
Jack the Bodiless (New York: Knopf, 1991). ISBN 0-679-40950-5.
Diamond Mask (New York: Knopf, 1994). ISBN 0-679-43310-4.
Magnificat (New York: Knopf, 1996). ISBN 0-679-44177-8.
The Trillium series began as a three-way collaboration. After the first book, the three authors each continued the series on their own.
Marion Zimmer Bradley, Julian May, and Andre Norton, Black Trillium (New York: Doubleday, 1990). ISBN 0-385-26185-3.
Blood Trillium (New York: Bantam, 1992). ISBN 0-553-08851-3.
Sky Trillium (New York: Del Rey, 1997). ISBN 0-345-38000-2.
The Rampart Worlds
Perseus Spur (New York: Ballantine, 1999). ISBN 0-345-39510-7. (First published 1998 in UK.)
Orion Arm (New York: Ballantine, 1999). ISBN 0-345-39519-0.
Sagittarius Whorl: An Adventure of the Rampart Worlds (New York: Ballantine, 2001). ISBN 0-345-39518-2.
Conqueror's Moon (New York: Ace, 2004). ISBN 0-441-01132-2.
Ironcrown Moon (New York: Ace, 2005). ISBN 0-441-01244-2.
Sorcerer's Moon (New York: Ace, 2006). ISBN 0-441-01383-X.