For the character, see Maghda.
Maghda, Leader of the Coven is a tome found in the Lair of the Witch in Act II of Diablo III.
It reads as follows:
When I joined the Coven, it was weak and idle. The leaders were content to do nothing, while the Prime Evils were imprisoned. I convinced another witch to help me poison them, and together we took control. She...left some years later, but I continued, bringing the Coven to glory under Lord Belial. - Maghda