In our line of work we collected data on the 11th–15th century settlement history of North-West Jászság both in historical and archaeological terms. The territorial boundary of the research was marked in the north-western part of Jászság. The time interval covered by the research was determined to be in the 11th–15th century. In the framework of the dissertation we intended to give an overview and summary of the examined area and period, thus revealing our current knowledge to research and those interested. In the course of the data collection we could build our research on the researchable archaeological finds, data archive documents and fieldwork results preserved in the collections of the Jász Museum and the János Damjanich Museum, as well as on the data in the official archaeological site register and the archaeological database of the Hungarian National Museum. Other sources of data were charters related to the medieval history of the area. A total of 85 medieval archaeological sites are currently known in the study area. The vast majority of these are settlement traces, but to a lesser extent there are medieval cemeteries and churches, four coin finds and a castle in North-West Jászság. In the framework of the dissertation, thanks to the excavation leader dr. Róbert Kertész, we also had the opportunity to process the material of the 2007 excavation at Jászfényszaru–Samsung car-park / Szőlők alja. We have knowledge of 14 settlements and estates in the study area which we know by their names from 13th–15th century charters and sometimes from later Turkish defters. In the first half of the 15th century, more villages, quarters and plains in Jászság appeared in the written sources. Based on historical and archaeological data, we outlined the history of the medieval settlements of the North-West Jászság, in which, besides the settlement network in the Arpad Period and in the late medieval times, we also addressed the influence of the Tartar invasion and the settlement of the Jász.