For all the wedding and engagement traditions that have changed over centuries—the introduction of diamond engagement rings, the shift towards weddings taking place outside of religious institutions, countless changes in fashion and style—the idea of getting down on one knee to propose really hasn't become any less popular. Most often it's still the man who drops down to the ground and pulls out a ring box (although sometimes it's the woman—or both women at the same time) though there's no clearly written beginning to this tradition, nor any reason you have to follow it if you don't want to. "It's storied, it's romantic because we've made it romantic, and because it's been included in so many love stories," says Lizzie Post, etiquette expert at the The Emily Post Institute, and author of "Emily Post's Wedding Etiquette 6th Edition." "Some people might prefer it just because they want that experience, and some people asking the question might just feel like it feels appropriate. It's how do you imagine yourself, how do you imagine your day, how do you imagine this moment?"
The idea of genuflecting—"to lower one's body briefly by bending on one knee"—has long been associated with showing "deference or servility;" some reports claim that as long ago as 328 BC, Alexander the Great introduced the practice into his court, and bending before emperors and royalty is a familiar practice for anyone who's studied history (or just watched The Crown—remember Phillip's (likely fictional) argument with Elizabeth as he resisted kneeling in front of her during her coronation?).
One common theory ties the genuflect in a modern proposal to the days of knights and chivalry, when a squire would kneel as he was dubbed a knight. While down on one knee, he would recite an oath that included promises to be truthful, loyal, devoted to his church, charitable, and to always "defend a lady," according to How Stuff Works—promises that seem not too different from the traditional wedding vows to love, cherish, and be faithful. Genuflecting also has a role in religious ceremonies in the Catholic, Anglican, and Lutheran churches as a sign of reverence and humility.
There could be a body language connection to the act of kneeling, too: In "The Psychology of Taking a Knee," Scientific American reports that "kneeling probably derives from a core principle in mammalian nonverbal behavior: Make the body smaller and look up to show respect, esteem, and deference." The impact of unlevel eye contact also may play a part, says Post. "In handshakes and introductions, for example, we talk a lot about eye contact—how it feels to have someone stand over you and have to look up at them, or, vice versa, to look down at someone, and how the dynamic changes based on whether someone is seated or standing. My thought is that you are asking someone to join you in life—which is a pretty big thing—and the idea of putting you up above them when you ask that question might be coming into play."
But, like the many other wedding traditions that have shifted and modernized since the days of courtly romance, an on-bended-knee proposal is a custom, not a rule. "Getting down on one knee doesn't change the question that's being asked, and I think, from an etiquette perspective, that's why it hasn't been a requirement," says Post. "But in general, if you have preferences or expectations about your engagement experience, that's something you should be sharing with your partner—if it means that much to you."