I've read through the FAQ, but non of the questions really fit, so I hope this one is okay.
From what I've read, it seems like being born female during the middle age is the worst destiny someone can possibly have. They had basically no rights, were treated as objects, got burned for being witches and genereally were the source of all evil.
I find that hard to believe, if it really was that horrible, I don't think that the first wave of feminism would have occured so much later.
So, how were women really treated in medial times? How many rights did they have? How was the power divided between men and women in a medival household? Simply, how sexist was society really? I'm mostly interested in europe, but answers for other parts of the world would for sure be interesting too.
Wow... this is a question that is best answered in at least a book, not a reddit post :). Remember, the medieval period was a period of roughly a thousand years, during which Europe had hundreds of regions with different, evolving cultures. Basically, any answer under 1000 pages long would be a gross oversimplification.
Simply but, it was "better than feared, worse than hoped."
In a nutshell, European medieval societies were patriarchal. The father was seen as the backbone of the family and in most cases acted as such. The Church, which was long the backbone of cultural life and education (to the extent one existed) was fairly patriarchal as well. The inheritance systems focused on men, since as noted it was presumed that the family is built around them.
Ergo, women were in a clearly inferior position compared to recent times and even parts of Antiquity. However, having an inferior position does not mean having no rights or no position whatsoever. There were laws and social codes on how women were supposed to be treated, although in the case of chivalric codes it was mostly about noble women. Peasants were, well, peasants. There were rules how to treat all others, based off the religious and local cultural codes, but it was often difficult to do something about a more powerful person abusing their priviledge. The basic unit of society was the family, not the individual. In the family, there was a clear hierarchy - the father, then the mother, then the children. Women were supposed to work (personally or with servants if their family was rich and noble), manage the household, and give birth to and raise the children. The only alternative was joining a nunnery, which was an exclusively female community and gave some options for leadership and literacy, but it came at a high price and was not something most women desired.
How it worked out in practice... varied. It varied by time, by place, by the characters of the people involved, by their families´s respective positions, etc. Generally, men had the stronger position, but there were many individual exceptions. The influence women had was mostly determined by how much personal influence they would have in their families or, for noblewomen, in their families´ domain. There are examples of noble families dominated by the woman or even of women who ruled domains, but that was because of their personal qualities and the situation they were in, not social position.
The influence of religion in the matter is complex. Christianity strongly stressed that women were weak and prone to temptation. On the other hand, the Virgin Mary was the highest of saints, and generally venerated almost as much as God. The image of women varied between saints and mothers and temptresses. So while religion probably weakened women´s overall position in society, it provided some cushions and limits to both their behavior and to the behavior that they had to be shown. It did not stress women as being evil, however. Weak, prone to temptation, possibly - although there were examples of the reverse in the Bible - but evil, no.
As for the burning of witches... that is generally not a medieval thing. During most of the Medieval period, burnings were quite rare and mostly focused on heresy, not witchcrafts, and heresy tended to be a charge mostly levied at priests, which women were not. Mass burnings of witches did not happen in Medieval Europe.
Also, remember, for an ideology for feminism to arise you need scholars and public people who support and advocate for it. You need an environment. Of course many people (mostly, but not only, women) were unhappy or protested abuse or unequal treatment of women, but overall, it was about individual cases which went against what was perceived as the proper position of women in society. The overall position was not challenged for a long time.
I agree that this is a post that is best answered in a book rather than a reddit post. The scope is just too big to cover in a short essay.
An excellent book on this topic is volume 1 of A History of Their Own: Women in Europe from Prehistory to the Present by Bonnie S. Anderson and Judith Zinsser. It is a well-researched book and covers the conditions and experiences of women of various backgrounds (the peasant at home, the noblelady in the castle, the merchant's wife, the nun in the cloister, etc.) and the social/cultural themes that created the backdrop of their lives.