In 1486 the king of Hungary, Matthias Corvinus, bestowed privileges of wine commerce upon the city of Retz. This meant that no foreign wine was to be brought into the territory of Retz. Only Retz citizens were allowed to store or sell wine. Since the Middle Ages the Retz farmers were also allowed to bring their wines to the market in Znaim/Znojmo. This was not seen well by the reigning sovereigns, who subsequently introduced export duties. The vintners reacted to this by devising a smuggling scheme, as wine was a much coveted commodity. Export barriers were erected in alternation on both sides. These were dropped in 1775 when toll reform was introduced. Wine commerce was concentrated primarily in the hands of large wine-trading families.
The Iron Curtain had a dramatic effect on the connection between the two cities. A border protection facility consisting of barbed-wire fences, mines, and watch towers as well as travel restrictions meant that the once lively exchange between the two sides practically dried up. In 1977 the mood along the border between Retz and Znojmo/Znaim was particularly frosty, when the supporters of Charter 77 (an informal civic initiative) demanded civil rights and freedoms. The nervousness of the communist government in Prague was also palpable at the borders. The Austrian authorities were requested to introduce measures informing the population about the strict adherence to border protocol. The logic went as follows: ‘the border area is the least suitable spot to collect berries and mushrooms.’ This request was complied with. In 1989 the Iron Curtain fell. Connections and exchanges were welcome once again, and partner city agreements were signed.