All wines entitled to carry the label Jerez-Xérès-Sherry and Sanlúcar de Barrameda are protected by the Denomination of Origin that guarantees their control from vine to bottle.
The Romans were the first to establish control over our wines, making it compulsory for the amphorae containing wine from the region to be marked with four "A"s. In 1483, the town council of Jerez issued decrees governing the export of wines and rasins and establishing the laws that should control the production and ageing of wine, the characteristics of the casks and the wood they should be made, as well as rules for grape harvesting and transportation. Only casks which complied with these regulations could be marketed with the town seal as a guarantee of quality.
On 27 October, 1733, the Consejo Real de Castilla (The Royal Council of Castille) endorsed the Decrees of the Wine Trade Guild regulating the storage, ageing and transport of wines from the the called Xerez (Sherry), even establishing a register of inns authorized to dispense Sherry.
Finally, in January 1935 the Consejo Regulador of the Denomination of Origin Jerez-Xérès-Sherry was created.