By the late 11th century, the western and northern parts of the Carpathian arc had become a significant region for trade and military activities. Despite its historical importance, the study of the northern frontier of the Kingdom of Hungary remains an underexplored topic in both Slovak and Hungarian scholarly discourse. This study highlights the complexity and research potential of the Árpád-Piast borderland, emphasizing the economical, cultural, and dynastic connections that shaped its historical development. Drawing on available historical and archaeological sources, primarily from the 11th century, the study examines the role of the Western Carpathian arc as a frontier zone between the Árpád and Piast domains. Key areas of focus include population mobility, mountain passes and their seasonal use, trade routes, and the territorial-administrative centres associated with them.