The first private postal service is documented for 1387, when merchants established a mounted courier service. The volume of mail initially remained low and was limited almost exclusively to merchants, the clergy, the nobility and royalty.
On October 17, 1558, the Polish King Sigismund II. August ordered Prospero Provano, a Venetian merchant living in Krakow, to organise a postal service in Poland. This is the documented beginning of the royal postal system in the territory of the Polish-Lithuanian Union, which was to unify the private services that had existed until then and to establish a "public" postal service.
At first, however, this only succeeded imperfectly. Between the 16th and 18th centuries, the royal house granted changing postal fiefdoms without succeeding in establishing a permanent and sustainable postal system. Thus, the House of Thurn and Taxis, Italian, Swedish and Saxon "postmasters general" alternated in quick succession. Only the postal service for the royal house functioned reasonably well.