About 100 years ago (being somewhat pessimistic about how long it will take me to write this), the Representation of the People Act was passed. Understandably enough, there’s been a whole bunch of comments regarding women getting the vote; and it was certainly a significant reform because of that.
But you have to hunt long and hard to realise that it also enshrined the one man, at least one vote principle (some University graduates could vote twice). Due to the previous property qualification, before 1918 only 60% of men could vote.
Which is almost as significant as giving women the vote.
Women got the same rights as men 10 years later in the 1928 Representation of the People Act.