Sulejów is one of the oldest settlements on the Pilica River. Its origins date back to the 10th century. However, the first mentions of Sulejów date back to the mid-12th century. Sulejów was known at that time under the names: Dulugov, Siliev, Sulev and Syrie[1.1]. Initially, Sulejów was a princely settlement (marketplace) with a customs collection point. Legend attributes the name of the town to Sulej, a knight who in the 11th century was supposed to have his ancestral home here. The development of the early settlement was probably related to its location in the Pilica River valley and the collection of tolls. There was a customs house on the river. Such a location must have had strategic significance. It was here that important trade routes crossed. The first of them led from Kraków to Toruń, constituting a part of the route leading from Hungary through Kraków to the Baltic Sea (the so-called Hungarian-Baltic route). The second one led from Kazimierz Dolny through Radom, Opoczno Sulejów to Piotrków, Widawa, Kępno with a branch towards Kalisz. These roads were for many years the main trade routes. Hungarian merchants used this route to Scandinavia, carrying copper and salt. The original trading settlement with a marketplace was located on the right bank of the Pilica, right next to the later abbey. Sulejów received location rights from Duke Władysław Łokietek in 1279, and city rights in 1308.