Marion Zimmer Bradley sets out to redeem the women of Arthuriana, specifically Morgaine (aka Morgan le Faye), in her retelling of the Arthurian legends, mostly taken from Malory's Le Morte Darthur and likely partly from White's The Once and Future King. 
 For the most part, she succeeds. Rather than a conniving, power-hungry sorceress, Morgaine is a very human, fallible woman who tries to do what she thinks is best for Britain. A priestess of Avalon, she watches in horror as Arthur gives more and more power to the Christians and subverts symbols of paganism, such as Excalibur, to Christian purposes. Believing that Britain must be ruled by someone who holds to the Old Ways, she attempts to place her stepson and lover, Accolon, on the throne, but succeeds only in causing further rift between Avalon and Camelot. 
 The issue I have with The Mists of Avalon is that there is no room in the novel for a strong woman other than Morgaine. Morgause is the same lustful, conniving woman who appears in Malory and White; Gwenhwyfar is an overly pious, judgmental woman who pushes Arthur to reject Avalon's counsel; and Elaine of Corbyn has been conflated with Elaine of Astolat and reduced to a handmaid who loves Lancelot too much. 
 Overall, however, Bradley has done a wonderful job at filling in holes left in Malory (why, for example, did Balyn kill the Lady of the Lake?) and humanizing the characters. It is easy to see why this is one of the seminal works of feminist fantasy literature, and one of the cornerstones of the genre.