Mother of God, by Miri Rubin.
Rubin, a history professor from England, presents an extremely well-research and detailed "history" of the Virgin Mary. In reality, it is a history of the Christian era of human history, using the Catholic Church as its focus, using the portayal of the Blessed Virgin as the narrative thread.
Rubin reviews (extensively) nearly 2 millennia of art, poetry, and songs of Mary, explaining how specific portrayals relate to a particular cultural view of the Virgin. She also covers theological and political developments as they relate to the Catholic Church and Mary's role in it.
The volume of notes at the end of the book place it firmly in the cAtegory of "academic," but is also manages to be a very readable and intersting work.