The tradition of a groom carrying his bride over the threshold, according to the historian Plutarch (46-120 A.D.), dates to the very founding of Rome (753 B.C.).
The custom finds its origin in the fact that the fledging city had a huge problem—no women. Their solution was to invite the neighboring Sabines to a party and, when all the guests were feeling pretty jolly, Emperor Romulus gave the signal for Roman men to carry off unclaimed women.
After the abduction, Romulus soothed tensions by promising each “taken” woman that they would “live in honorable wedlock, share in all their property and civil rights, and would be the mothers of freemen.” Going a colossal step further, he assured them that in their Roman husbands they would find more affection than in all other men.
All of this must have come to pass, for when the fathers of the Sabine women finally returned with an army a number of years later to get them back, the women themselves intervened. The battle was stopped, peace was made; Rome had its wives and the Sabines their daughters. And so the ritual of a bride being lifted over her husband’s threshold into a new life is credited to the Sabine women who were carried off to their destiny 2,765 years ago.