The author sets out to verify some of the opinions prevailing in historical writings on the foundation of the town of Bydgoszcz (1346) and its further development in the 14th c. His findings differ in some important points from what has been accepted in the literature and cast new light on the urban policy of King Casimir the Great. Among the convictions questioned here is first of all the view that at the moment of the foundation Bydgoszcz was planned as a whole on the area delimited by the town walls. Had it been so, about 300 plots would have been delineated and built over in a very short time. It seems, however, that the urban structure grew gradually, and that initially only the area around the marker square was parceled out. The second phase was probably the marking of plots in three blocks opposite the marker square corners, and the third -at the southern side of Dluga Street. Around 1370 the town had 150 plots. Further corrections of the street network, consisting in marking out Mostowa Street and the place for a new church, took place before 1398. According to the foundation charter, the initial town territory (patrimonium) covered quite a sizeable area (about 95 square kilometers), but it was not as large as it is suggested in some publications. By delimiting such extensive boundaries of the town Casimir the Great intended to subject to the municipal authority some areas that had not been under the jurisdiction of other municipalities or Church institutions. The conclusions presented here need to be further verified against historical and archaeological sources. Only interdisciplinary research can lead to a thorough examination of the past of this important urban centre.