The Mists of Avalon by Marion Zimmer Bradley

This is the story of the women in Camelot and King Arthur's court, told from their perspective with Morgaine, a priestess and sister of Arthur, as the main voice.
You have heard the legend of Arthur before but not in this way or with this emotional appeal.
A child from Morgaine's mating with Arthur, under the guise of the King Stag in a sacred ceremony, haunts them throughout their lives.
But that is a small backdrop to the richness of the story set at the time of the ending of the reign of the goddess and the druidic beliefs in Britain as Christianity entered to replace the old religions.
Not a new novel, published in 1982, this is a great read if you have never read it before, love novels, enjoy historical intrigue or simply want to enjoy the experience again.
I have finished the 876 pages at least nine times in the past 20 years, and with each reading I find myself lost and immersed in the lives and actions of Morgaine, Gwinevere, Morgaine's mother and aunt who struggle to fulfill their roles of queens and servants to the goddess.
Their lives and tasks were not easy.
Women are the focus, women with their strengths and flaws; this is not a rosy feminist picture but an assessment of what makes us human, the good and the bad.
Without spoiling the ending or providing more of the excitement encompassing this story, I simply want to share a quote from the novel, words that speak particularly to those of us much too critical of ourselves and our actions: I did not fail.
I did what she [the Goddess] had given me to do.
It was not she but I in my pride who thought I should have done more.