This is not a question that can be answered, because trying to do it would create an unrealistic world.
A culture is derived from the circumstances, limits, and enviroment a society lives in. Roles, taboos, practices etc etc are developed because they make sense and fit with what is required by that society, generalized in rules that everyone is raised to abide by until they become unconscious habit passed on through generations. In essence culture evolves, in a way very similar to the way animals evolve. Over time it will naturally adapt and change to fit the constraints of that society.
A realistic culture must be one that evolves from the world it is set into. This is a pet-peeve of mine because I see so many would-be authors create worlds with a culture they thought was cool without any thought to how it would evolve, and it breaks suspension of disbelief if the culture doesn't make sense. I can be as offended by a culture that doesn't fit it's enviroment as I would an author that tries creates a creature a 'more efficient' animal where 4 females are born to every one male without regard for the fact that evolutionarily this wouldn't happen due to Fisher's principle
Horrible things have evolved in creatures, from species were one creature has all power, be they queen ants or gorilla alpha males, to evolve increasingly elaborate rape techniques-most horrible being the bedbug's "traumatic insemination" where they literally stabs females in the gut to force impregnation. to lots inevitable horrible deaths, like say any R strategy creature that produce thousands of young knowing almost all of them will die a quick painful death. There are mites where the male lives only long enough to mate with his own sisters while still in the womb then dying before being born, which is still better then a breed of shark where the young have to literally fight and kill their siblings while still in the womb to earn the right to be born. However, these are the results of evolution, rather we like them or not they proved adaptive to pressures placed on the species.
Likewise a proper consideration of culture relative to one's world will occasionally lead you down some dark paths you really don't like, infanticide, racism, infidelity, and of course gender inequality being examples. It's not right, it's not fair, and it's not something we should tolerate today, but it is a very likely result of the 'evolutionary pressures' placed on the culture of the past.
You can't ignore such pressures or what they would create out of hand without breaking suspension of disbelief. If you don't like the end result of a given 'evolution' the correct world building solution is to modify the pressures placed on your culture so it will evolve in a different way, in other worlds change your world. but don't change your culture without touching the world that surrounds it.
I would in particular note that many, in fact the vast majority, of pre-modern cultures around the world have developed gender-unequal societies. Truly gender equal, or even close to gender equal, pre-modern societies are very very rare. In some cases the women have had the gender advantages, on others there have been situations were the two sides had gender advantages in very disparate areas. However, the fact is that the statistical majority of cultures, even those isolated and developing culturally independently of each other, have developed cultures in which women were placed in an unfair gender role relative to men. I don't like it, I've faught to try to fix our current culture, but the fact that this culture independently evolved in so many societies shows that the evolutionary pressures on pre-modern humans are ones that will encourage gender inequality, that is the likely outcome. Thus it's up to the author to put in effort to justify modifying these evolutionary pressures if they want a different evolution.
In the particular case of gender equality the cultural evolutionary pressures comes down to child rearing predominantly. In the past women had to devote extensive effort to wearing children or children would not be developed. Children died frequently and many many children had to be raised simply to ensure some made it to adulthood. They had to be breastfeed by a women, no formula existed. The need to be available to breast feed, the limitations of being pregnant on a semi-regular basis (at a time when it was harder to be pregnant and risk of complications preventing carrying a child to term were greater) meant that women who wanted a family had to stay close to home.
This in turn lead to men having both jobs that required travel and also jobs that were more dangerous, because frankly men are less important sex from a reproductive standpoint.
Now factor in the fact that men are, on average, physically stronger then women. The men are the ones who are trained to fight, because soldering involve both danger and being away from home for long lengths of time which were not options for child-rearing women. Men are now both better armed naturally and better training in fighting then a women. Additionally, Since a women is limited in her ability to work by pregnancy, breast feeding, and other child rearing tasks that would naturally fall on the person who has to be around to breast feed anyways, the man is in a better position to do work outside of the home to earn money.
Therefore you have a clear imbalance of power, men have physical strength and additional resources (money) that women don't. Men would likely be tempted to abuse this imbalance of power to get what they want, make a women more dependent on them and they can then make more demands from her. Part of exploiting this power difference is by further limiting women's resources so as to ensure that you will maintain your advantage, thus the tendency to discourage education, forbid voting, claim a superior male intellect that didn't exist, and many other unfair restrictions placed on women in the past.
To claim that gender inequality did not occur ever in the past would require you to say either
1) That men did not have a clear power-advantage compared to women due to of physical and also inevitable necessary gender role divisions (child rearing).
2) That men would not take advantage of a power-advantage to gain privileges and enforce their will on others. And to think ANY group of humans would not exploit a power advantage to take what they wanted from another at any point in our history is....well to ignore about 85% of that history.
Now the first option can be done, as an exercise in world building you can always change parts of your world to encourage evolution of different societies. Here's an example:
The far better gender roles of today are likely due to the decrease of the inherent imbalance thanks to modern technology. There is less of a need to pop out child after child with mortality rates so much lower. Women do not suffer nearly as much from their statistically lower strength now that guns and other technology serve as a force equalizer, and there is no need for a women to stay at home to breast feed a child instead of working to provide for herself if she so chooses (though breast-milk may be a little healthier for a child, depending on what research you look at). Finally, our needs in the job market are now predominately for intellect, where women and men are equal footing, and to a lesser extent social skills (think Human resources, communication, planning etc) which women may actually have a slight evolutionary advantage.
In short technology has removed many of the imbalances between the sexes. This has resulted in societies with this technology evolving culturally. There no longer are the same evolutionary pressures on our culture, and so it slowly adapts to make optimal use of the skills and talents of both sexes.
Now keep in mind that culture, like regular evolution, can be slow to adapt. Take a snapshot of any time period and your find 'legacy culture', things from a past culture that made sense in that culture, but are not applicable to the current enviroment. Just as species take a few generations to adapt to sudden changes in enviroment our culture takes awhile too. I would argue that most of the current gender issues of today are largely due to this legacy culture that hasn't fully adapted yet to our modern society and technology. I think we have a very real hope that in a generation or two we will be...well still not perfect because humanity is never perfect, but at least mostly have forgotten current gender disparity in favor of 'better' gender roles (ideally no gender role would exist, but it's not realistic to expect that given flawed human nature, at least the roles will be less pronounced and not place one sex at a clear disadvantage when fulfilling whatever it's new gender role is).
To give an example of good culture evolution let me point to my favorite author, and one that I like particularly because she clearly shows her work when justifying cultural evolution and world building.
In the Lois Mcmaster Bujold's Vorkosigan Saga she wanted a world with modern technology but with a feudal style government and military/culture obsessed culture that felt more at home with a swords and sandles style book (effectively she wanted Klingon...no really it was inspired by star trek Klingons, even if they aren't that much like Klingons in the final version) .
She correctly recognized that normally a feudal military cast culture would not normally evolve within the world, and technology, she had in mind. She wished to justify it though, so she modified her world. Specifically her home planet, Baryar, was cut off from the rest of the universe by accident many generations ago, and revert in both technology, government, and culture, as they struggled to survive in desperate situation. The 'present' baryar is set a 2-3 generations after Baryar reconnects with society and future technology. Their culture has not yet adapted to the technology, and in many cases shows foolish decisions because they are still stuck in old ways that don't make sense. Infanticide for mutations, once required due to the small genetic pool making the risk of mutations severe enough to risk collapse of society, is still occasionally practiced in the backwaters of a world where they can use gene sweepers to prevent mutations from being passed on and possible fix the damage done by it. People refuse to use new Uterine replicators which are safer then 'body births' etc. Further more, upon realizing the inevitable ingrained cultural fear of mutation would evolve from such a small gene pool and high risk of mutation she ended up using that cultural hatred of mutation to great effect by having it's effects on her protagonists, who appears to be a 'mutant', complex psychology and need to prove himself.
She uses the slow speed of cultural evolution to have her cake and eat it too by justifying a culture that otherwise would feel out of place with enviroment. More importantly she then asked what else would evolve from such societal pressures as a small group of strangers stranded on inhospitable world, realized a cultural hatrid of mutation would evolve from inbreeding concerns, and used that fact to help further create her world and characters. This is how world building should be, ask how your culture evolves, adjust the world to encourage the evolution you want, and then deduce what other accidental evolutions come from those changes, repeat until you have a fully fleshed out world.
The point of my tangent being that this is how any question of equality in pre-modern societies should be addressed if you want to see it happen, change the pressures on the society to justify it, then see what kind of interesting world evolves out of those changes. The greatest harm to consistent worlds you can make is to choose to ignore the evolution and implications of the world you created on the inhabitants of it, even if they are things you don't like. For your world to be real you must either acknowledge what you don't work or find a way to change the world so it doesn't evolve.