The Privilege of Koszyce was a set of concessions made by Louis I of Hungary to the Polish

Poland

Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...

 szlachta

Szlachta

The szlachta was a legally privileged noble class with origins in the Kingdom of Poland. It gained considerable institutional privileges during the 1333-1370 reign of Casimir the Great. In 1413, following a series of tentative personal unions between the Grand Duchy of Lithuania and the Kingdom of...

 in 1374. The privileges were granted in Košice

Košice

Košice is a city in eastern Slovakia. It is situated on the river Hornád at the eastern reaches of the Slovak Ore Mountains, near the border with Hungary...

. In exchange, one of Louis' daughters (Catherine

Catherine of Hungary (1370-1378)

Catherine of Hungary was the eldest child of King Louis I of Hungary and his second queen, Elizabeth of Bosnia.-Heiress presumptive:Catherine's birth was long expected, as her parents' marriage was childless for the first seventeen years...

, Mary

Mary of Hungary

Mary of Anjou was queen regnant of Hungary from 1382 until her death in 1395.-Childhood:...

 or Hedwig) was to ascend the throne of Poland after his death.

Szlachta

Szlachta

The szlachta was a legally privileged noble class with origins in the Kingdom of Poland. It gained considerable institutional privileges during the 1333-1370 reign of Casimir the Great. In 1413, following a series of tentative personal unions between the Grand Duchy of Lithuania and the Kingdom of...

 obtained undermentioned privileges:

• tribute release, with the exception of 2 groschen
  Groschen
  Groschen was the name for a coin used in various German-speaking states as well as some non-German-speaking countries of Central Europe , the Danubian principalities...
  
  s from one field and 4 groschen from monastic properties,
• release of duty of building and repair castles, with the exception war,
• offices only for poles,
• Szlachta for fight on the war got soldier's pay,
• release of building towns and bridges,
• release of support king's court when he was voyaging in the kingdom.

The privilege was a success, as Louis' youngest daughter Hedwig succeeded her father as monarch of Poland without opposition.