I know this probably varies wildly based on social position and other things, but the question is inspired by the history of upper-class women marrying for socially strategic reasons, often arranged without her input. When did the acceptance of the woman herself become normalized, and before that, were there ever socially acceptable ways for a woman to avoid an arranged marriage?
This is a tricky question, because the two things you're talking about - a woman's consent and arranged upper-class marriages - were not mutually exclusive.
Consent was crucial to marriage in Christianity from the middle ages on: debate raged over what exactly constituted a marriage, but the one thing agreed upon was that both individuals had to agree to be married for it to be valid. Pope Alexander III (ca. 1100-1181) decreed that a man and woman who affirmed their consent, even privately and without consummation, had formed a marriage (although it would not be completely indissoluble until the couple had sex); later acts would require priests, publicity, etc. but always on top of consent.
Where things get tricky is that "consent" could be very liberally interpreted. Consider the following scenarios:
- It's 1450. You are a twelve-year-old orphan, the only daughter of a wealthy aristocrat. The king made his cousin your guardian five years ago, and now that you're of age, he wants to marry you to his fifteen-year-old son, which will give his son your money and, the king promised, your father's title. It is treated as a fait accompli, you're told what to say and where to stand, and your husband has always been nice to you, anyway.
- It's 1650. You are a minority religion, and your parents are very insistent that you marry within it. They've found a young lord with the same religion and had him over for a long visit, and they've made it known to you that they've given their blessing to his proposal well in advance. A few days before he goes home, he proposes and you accept, because you're going to get married at some point and this seems as good a chance as any - plus your parents are happy with him.
- It's 1850. Your father lost his money in speculation and your family has fallen on very hard times. You're also approaching twenty-five, and once in your late twenties and without a dowry you know that you will never get married. A family friend tentatively approaches you and says he appreciates your many sterling qualities, and will marry you if your father approves. He doesn't say that he's not in love with you, but you know this is to help your family have one less mouth to feed and to give you your one chance at marriage, and you accept.
We can perceive a difference between a passive acceptance and enthusiastic consent, but they are at two ends of a spectrum, and historically a passive acceptance was often expected and allowed to be considered consent. But that acceptance was always, throughout this timespan, required - if a young woman were brought to the altar by force and refused to verbally consent to the marriage, she would most likely/legally not be considered married. That being said, passive acceptance could be brought by many means, if a parent or guardian cared more about the marriage taking place than their child's feelings, and there are a number of stories (particularly from the High Middle Ages, around the same time as the debate about consent was occurring) relating the means parents could go to in order to force a marriage with an unwilling daughter. Christina of Markyate (ca. 1097-1155), for instance, was said to have been kept under guard and subjected to, alternately, threats and bribes, all of which failed - thus showing her piety, and also the importance of a daughter giving some level of non-negative response to the question of whether she would be married.