The city was made of two independent settlements: Lower Kassa and Upper Kassa, amalgamated in the 13th century around the long lens-formed "ring", of today's Main Street. The first known town privileges come from 1290. The city proliferated because of its strategic location on an international trade route from agriculturally rich central Hungary to central Poland, itself along a greater route connecting the Balkans and the Adriatic and Aegean seas to the Baltic Sea. The privileges given by the king were helpful in developing crafts, business, increasing importance (seat of the royal chamber for Upper Hungary), and for building its strong fortifications. In 1307, the first guild regulations were registered here and were the oldest in the Kingdom of Hungary.