William Barnwell is an author perhaps best known for the Blessings Trilogy. The trilogy is deeply concerned with metaphysics and set in a future Ireland. It was praised by Andre Norton, but Peter Nicholls theorized that the author wrote like "a member of a pseudoscience cult." Despite this, his verdict on the writing was not entirely negative. The series was published from 1980 to 1981.

In 2001, Barnwell returned to the genre with Book of the Romes, a historical novel with SF/F elements. He currently resides in Hartsville, South Carolina.