The expression "to tie the knot" means "to get married".   There are several places where tied knots have been connected to marriage and love.

During Roman times, brides wore a belt or girdle at their wedding tied in a Hercules Knot. Only the groom was allowed to untie it (the unloosening was supposed to be a further symbol of childbearing).  The knot was supposed to represent the binding character of the marriage oath.

A Hercules Knot:

Then there’s the True-Love’s Knot from Scotland, England and Denmark which were given as a symbol of love and fidelity to one’s beloved. 

Ribbons with true-love knots were also given out as bridal favors at weddings. In Great Britain, they put these ribbons in their hats.  In France, they were worn around the arm.  At first the ribbons came in different colors, but eventually just white ones were used.

One example of a True-love’s Knot used at weddings:

In Hindi wedding ceremonies, they tie together the bride’s garment to the groom’s scarf (as you can see in the video below).  This symbolizes a life-long bond. The knot should not be untied until the ceremony has been completed.

Hindi brides are also given a yellow or gold necklace called the mangalsutra during the wedding ceremony.  The groom ties it unto his bride. (See video below.) Three knots may be tied into the necklace too.

Sometimes the bride and groom’s hands are tied together during wedding ceremonies.

In the Philippines, they put a cord over the bride and groom’s shoulders to signify everlasting fidelity.

In France, there’s a different shade of tying a rope.  They have the phrase "passer la corde au cou de quelqu’un" which means "to get married".  But it has slightly darker undertones since it literally means, "to pass the rope around someone’s neck."  I suppose there’s some humor in that phrase.

Please feel free to share other traditions and expressions that involve tying the knot in the comments below.

-Mama Lisa

Image of Mangala sutra: Wikipidia

NOTE: I just learned about an Iranian New Year’s Tradition of tying a knot in grass in hope of getting married the following year.