Romans were probably the first to experiment with the preparation of mustard as a condiment. They mixed unfermented grape juice, known as "must", with ground mustard seeds (called sinapis) to make "burning must", mustum ardens — hence "must ard". A recipe for mustard appears in Apicius (also called De re coquinaria), the anonymously compiled Roman cookbook from the late 4th or early 5th century; the recipe calls for a mixture of ground mustard, pepper, caraway, lovage, grilled coriander seeds, dill, celery, thyme, oregano, onion, honey, vinegar, fish sauce, and oil, and was intended as a glaze for spit-roasted boar.
The Romans likely exported mustard seed to Gaul, and, by the 10th century, monks of St. Germain des Pres in Paris absorbed the mustard-making knowledge of Romans and began their own production. The first appearance of mustard makers on the royal registers in Paris dates back to 1292. Dijon, France, became a recognized centre for mustard making by the 13th century.
The popularity of mustard in Dijon is evidenced by written accounts of guests consuming 70 gallons of mustard creme in a single sitting at a gala held by the Duke of Burgundy in 1336. In 1777, one of the most famous Dijon mustard makers, Grey-Poupon, was established as a partnership between Maurice Grey, a mustard maker with a unique recipe containing white wine, and Auguste Poupon, his financial backer. Their success was aided by the introduction of the first automatic mustard-making machine. In 1937, Dijon mustard was granted an Appellation d'origine contrôlée. Due to its long tradition of mustard making, Dijon is regarded as the mustard capital of the world.
An early use of mustard as a condiment in England was in the form of mustard balls — coarse-ground mustard seed combined with flour and cinnamon, moistened, rolled into balls, and dried — which were easily stored and combined with vinegar or wine to make mustard paste as needed. The town of Tewkesbury was well known for its high-quality mustard balls, which were exported to London and other parts of the country, and are even mentioned in William Shakespeare's play King Henry the Fourth, Part II.
The use of mustard as a hot dog condiment was first seen at the 1904 St. Louis World's Fair, when the bright-yellow French's mustard was introduced by the R.T. French Company.