As far as medieval Mostar goes, although the Christian basilicas of late antiquity remained in use, few historical sources were preserved and not much is known about this period. The name of Mostar was first mentioned in a document dating from 1474, taking its name from the bridge-keepers ("mostari"); this refers to the existence of a wooden bridge from the market on the left bank of the river which was used by traders, soldiers, and other travelers. During this time it was also the seat of a kadiluk (district with a regional judge). Since Mostar was on the trade route between the Adriatic and the mineral-rich regions of central Bosnia, the settlement began to spread to the right bank of the river.