Complex sentence: After Harrow received her third degree Gardnerian initiation in November, 1980, this group became Proteus Coven, which thereafter affiliated with Covenant of the Goddess in August, 1981.
Split into simpler sentences: After Harrow received her Third Degree initiation (Gardnerian) in November, 1980, this group became Proteus Coven. Proteus affiliated with Covenant of the Goddess in August, 1981.