Based on this topic, and the question raised by /u/oldmandubya; what was the deal with Christian women covering their hair during (part of) medieval times? (e.g. this painting); was it practicality, assuming that men go wild when seeing a lock of hair, something else?
The milkmaid is a painting from the 17th century (specifically the Dutch Golden Age) - do you mean to ask about the 17th century, or the early/mid/late middle ages?