
Historians do not have a clear idea of when the engagement ring became a standard gift to symbolize the promise to wed. The tradition of the future husband giving his intended an engagement ring may have begun in ancient Rome. It is certain that the exchange of rings in the marriage ceremony predates the giving of an engagement ring, and that the customs related to engagement itself also existed long before the engagement ring became the most prevalent custom.
Traditionally, the seriousness of marriage was marked by the level of material exchange of household wealth. The bride's family was expected to provide a dowry, which often represented a significant portion of her family's assets. The groom's family, in exchange, usually paid a somewhat lesser bride price. The engagement ring may be a custom that is distantly related to this payment of a bride price, similar to the custom of the bride's family paying for the expenses of the wedding-- derived from the expectation of providing a dowry.
Historical records in Europe show that future grooms from wealthy aristocracy, royalty, and the ruling classes gave engagement rings to their beloveds beginning in the mid-15th century. This coincides with the rise of the traditions of Courtly Love, with the wealthy and privileged classes more free to romanticize marriage, and extend it beyond its practical economic, political, and social purposes.
People have, of course, been falling in love at least for as long as recorded history, but it has only been fairly recently that these feelings of attraction have formed the basis for courtship, engagement, and marriage. Traditionally, in communities that had a definite class structure, marriages were arranged to preserve the status quo, a practice continues even today in non-Western cultures. The engagement ring as a gift of love roughly coincides with the advent of marriages of choice. This may be due to the fact that the giving of an engagement ring at the moment of the marriage proposal more emphatically signified the choice of the betrothed, and made the event both more romantic and more private.
Many different types of engagement rings were given as symbols of binding promise, including rings made of every metal from gold to iron, set with no gems at all, or emeralds, rubies, sapphires, and of course diamonds. In a variety of pre-Christian religions, simple wreath of interwoven rushes, or a small ring woven from the hair of the betrothed, were used to represent a future commitment. The practice of marking a deep and binding promise through the giving of precious jewelry is ancient.
The prevalence of the tradition of the diamond engagement ring dates to the 1800's in Europe and America. Diamonds were at first exceedingly rare, and their hardness, brilliance, and value lent an extravagant air to the act of proposal. As the 1800's unfolded, more diamond veins were discovered and the gem became more widely accessible. Smaller diamonds became relatively affordable even among less wealthy members of society. The diamond industry grew, and clever marketing such as the "Diamonds are Forever" ad campaign of the DeBeers company resulted in the diamond being the standard gem for engagement rings. The near-indestructibility of diamonds, combined with their crystalline purity and light-reflecting dazzle, makes them the perfect stone to symbolize the serious commitment to marry.
Engagement rings in general now are offered in a huge variety of styles, with or without diamonds. Diamond settings are still the most common, with the price of rings ranging from millions of dollars to a few hundred. In many cases, a diamond engagement ring is the third most expensive purchase made in a person's lifetime, but it is also an easy matter to obtain a beautiful, durable, and meaningful ring at an affordable price.