Mayonnaise is used a lot in American cuisine, but it's classically associated with French fare. “Mastering The Art of French Cooking” credited mayo as being the leader of a wide array of sauces, including rémoulade and tartar, but its origins are still unclear.

In 1756, French forces created “mahonnaise” while in Port Mahon, Minorca, an area that is now a part of Spain, during the Seven Years’ War, but it might have been based on Minorca’s “Salsa Mahonesa.” However, mayo didn’t show up in French texts until 50 years after the battle for Port Mahon, so this story may be false and the true origin is lost to time.

One thing we can say for sure is that mayonnaise was not the first sauce to exist, as mayo is probably a spiritual successor to aioli, an emulsion of olive oil, mashed garlic, and salt. We know aioli is older as a Roman historian documented aioli's existence in the first century A.D.