When speaking of the fairs we must also first speak of their origins, which traditionally date back to the beginning of the XV Century.

Fernando de Antequera is held to be the founder of said fairs around 1404, which to begin with were of a stately nature, the same as those established in Medina del Rioseco or Villalón. Some say that the fair model adopted was the one created in the town of Cuellar in 1390, by Don Fernando himself.

On the 12th of April of 1421, the first settlement Ordinances were pronounced for the fair exhibitors, pronounced by the wife of Don Fernando, Doña Leonor de Alburquerque, then Señora de Medina. Thanks to her we now know where each of the exhibitors was installed with their merchandise during the XV Century.

• In the Plaza Mayor: Chair makers and brakemen, jewellers, spice merchants, gunsmiths, hosiers and makers of chainmail, peddlers and barbers.
• Calle Padilla: Bills of exchange and cloth.
• Calle Gamazo, old Salamanca streets: Tallow, oil, esparto fish and wax merchants.
  
• Plaza del Pan and surroundings: Furriers and underwear.
• Calle Bernal Díaz del Castillo: The silversmiths.
• Calle claudio Moyano: Blacksmiths and boiler-makers.
• Calle Valladolid: Cobblers, leather and Cordovan merchants.
• Zona de la Mota: Saddle-makers.
• Calle Maldonado: Drapers and silk merchants.

That was the configuration on the map of the trader’s locations.

These Fairs have enjoyed constant Royal favour since their foundation, during the reign of Henry IV and John II of Castile, as well as in the reign of the Catholic Monarchs, with 1491 being when they came to be considered as general fairs of the Kingdom.

As well as Royal favour, the prime location of Medina also played an influential part as a crossroads (above all the Toledo-Burgos axis) which united Castilian routes such as Valladolid, Zamora, Salamanca, Segovia and Ávila.

These fairs had two notification periods, in May and in October, both lasting approximately 50 days each.

To begin with they were free markets for the transaction of products but over time they became eminently financial fairs. Similarly, they went from the protagonism of exhibitors and merchants to that of business agents, money changers and bankers, such as for example, Simón Ruiz.

It was not unusual to find amongst the merchants from Burgos, Seville or Cataluña, business agents (bankers and money changers) from Antwerp, Lyon, Genoa, Florence or Lisbon; these business agents endorsed credits, sent notice letters, contracted large orders, ordered payments and fundamentally remitted bills of exchange.

With regard to bills of exchange, it is in this period, in the XVI Century, that they crystallize and acquire their definitive working shape (the widely held belief that the bill of exchange was invented in Medina del Campo, is not true as it was already common in much earlier trade meetings, as in the case of Italy).
In the Museo de las Ferias we have the rolls of the monument dedicated to the bill of exchange.

From the 2nd half of the XVI Century, there were economic crises, related above all to the serious indebtedness of the Crown, plunged into continuous wars, leading to:

"Definitive suspension of payments such as those of 1575 and 1596, the latter being controlled for a short while thanks to the reforms of 1578 and 1583".

Until October 1594 (moment at which the definitive crisis appears, together with the commercial schism with Flandes and the transfer in 1606 of the Courts to Madrid.
This implied the breakdown of the financial system and total crisis. A battered existence was led until the reign of Phillip V (XVIII Century 1700-1746)..

Then in the second half of the XIX Century, favoured by the arrival of the train in 1860, new fairs arise, but of a regional nature; these fairs are strengthened with the creation of the weekly livestock market in 1870, which is joined by the grain and cereal market in 1871.

The Feria Mayor de San Antolín (Major Fair of St. Antolin) in 1873, with an initial duration of 6 days and from 1878 of 8 days, as it remains currently.

Small San Antonio fair in 1877.

These fairs give a new impetus to Medina converting it into one of the main centres for contracting wheat and livestock (above all, ovine), without following the path of the XV and XVI centuries.

These Fairs have reached our days still in force but transformed by the passage of the years.

Due to the creation of the weekly Sunday market in 1870, this tradition has been upheld in the Town, with the opening of establishments and shops on Sundays, whilst closing on every Thursday throughout the year.