Many of the Middle Age artists were women. The identity of some of these medieval artists has been lost because women got married or changed their names when they became nuns. The nuns didn't normally sign the illuminated manuscripts they created; they had turned away from worldly praise. Some did sign their work, especially if she was an abbess.
Women of wealth got an education as nuns and were given task like illuminating manuscripts, if they had artistic talent. Their drawing pad was a wax tablet. The design may have been traced on vellum first. It was expensive to produce the illuminations for Bibles and Holy books, so anyone given this work was considered skilled and trustworthy.
Bishop Caesarius founded the first western convent in Arles in 512 A.D. He wanted the women to paint illuminated manuscripts, when they weren't reading the Bible, holding vigils, and praying. His sister,Caesaria, become the head of the nunnery.
Sometimes dealers would resign paintings using the name of a well known male artist, if the style was similar, thereby increasing the paintings value. According to Nancy G. Heller it was assumed by some people that a woman couldn't paint well, thus the painting would be attributed to a male art teacher or relative.
These are some of the women manuscript iluminators: Claricia (12th c.), Herrad of Landsberg (1125-1195), Ende (11th c), Gunda (12th c), Diemud (1057-1130), and Hildgard (12th c), Bourgot (14th c).
Book about Hildegarde de Bingen
Women, Art, and Society