[2][3][4][5][6] The San arises in the Carpathian Mountains near the village of Sianky, at an elevation of 900 metres (3,000 ft), exactly on the Polish-Ukrainian border[7] (49°00′10″N 22°52′30″E / 49.00278°N 22.87500°E / 49.00278; 22.87500) and on the continental watershed, and forms the border between Poland and Ukraine for approximately its first 50 km (31 mi).

[8] Humans had first settled the southeastern region of present-day Poland (the Subcarpathian Voivodeship or Podkarpacie) in prehistoric times.

The San valley must have become an important trade-route and axis of human settlement as early as the 9th or 10th century.

The region then became a site of contention between Poland, Kievan Rus and Hungary starting in around the 9th century.

This region, including the area west and east of the Subcarpathian Voivodship, was controlled by Austria for almost 120 years.