Through various archeological discoveries, scientists believe that the earliest civilization with a custom akin to our modern day engagement ring was that of ancient Egypt. Believing that there was a special vein, known as the vena amoris, that connected the fourth finger of the left hand directly to the heart, the Egyptians exchanged primitive wedding bands of braided sedges, rushes and reeds. The round circle, with no beginning and no end, was a symbol of endless love and the hole in the center was a gateway or door to the unknown future together. The materials of these early rings were fragile and wouldn't last long so they were later replaced by leather, bone, and ivory.

The Egyptians are sometimes also credited with the invention of the puzzle ring, though there is debate about its origins. Many believe it was the sheiks and chieftans in Arabia that first used this tool of fidelity. Puzzle rings were complex pieces of jewelry, consisting of several rings, that formed one cohesive band when worn correctly. If a woman were to try to take the ring off in order to be unfaithful, it was believed that she would be unable to piece the ring together to put it back on and hide the infidelity from her husband (apparently it was too much to even comprehend that she would simply leave her ring on during the evil deed).

The earliest association between diamonds and romantic love seems to be the Roman notion during the first century AD that the magic of Cupid’s arrows came from their diamond encrusted tips. Though diamonds were highly valued at that point (the Roman philosopher Pliny called them the most valuable of all things in the world), they were still not a part of the betrothal process. The Romans instead exchanged modest bands of iron to signify strength and permanence and as a symbolic token of a mans ownership of the woman. Later some wealthier Romans began to use gold for these rings.

During the dark ages the gifting of engagement rings seems to have all but disappeared and was revived in approximately 1215 when Pope Innocent III, one of the most powerful popes of the middle ages, changed some of the rules surrounding marriage. One of his new decrees was that there was to be a waiting period between the betrothal and the marriage ceremony. A gold ring was then given to the bride as a formal pronouncement of the intention to marry and to symbolize the groom's financial commitment.

There are no recorded instances of a diamond being given in an engagement ring until much later in 1477 when the Archduke Maximilian of Austria proposed to Mary of Burgundy. The Archduke presented his soon-to-be bride with a ring set with thin, flat pieces of diamonds in the shape of an “M”. Nobles at this point often gave their brides-to-be pieces of jewelry so it was unlikely to be thought of as significant at the time that the ring was of diamonds. A few years later in 1518, another notable diamond ring was presented – the smallest engagement ring on record was made for the 2 year old daughter of Henry VIII, the Princess Mary, on the occasion of her engagement to the baby Francois, Dauphin of France.

For many years diamonds remained a stone exclusively for the elite. It wasn’t until 1867 when huge veins of diamonds were discovered in South Africa and the market became flooded with the shiny baubles that they had the potential to become a common commodity as prices were driven down. In 1888, to take control of this and staunch the hemorrhaging of prices, Cecil Rhodes, a British businessman living in South Africa, and a group of partners merged several major South African mines together and formed De Beers Consolidated Mines, Ltd. The group was able to effectively control the flow of diamonds into the market, creating the illusion of rarity and upping the value of the gems. Within a decade the De Beers group would control 90% of the world’s diamond production.

But the diamond engagement ring wasn't firmly stamped into American tradition until De Beers began working with New York ad agency N.W. Ayer in the late 1930’s and 1940’s. The resulting campaigns included images of Hollywood stars dripping in sparkly diamonds, leading fashion designers were paid to talk about diamonds as an emerging trend and in 1947 De Beers rolled out their most famous slogan “A Diamond is Forever”, thus inextricably linking the diamond to the everlasting bonds of love in the American consciousness.