BY THE 1530S AND 1540S, PRODUCTION OF SILVER REACHED ITS PEAK WHEN 3500 KG OF PURE SILVER WERE EXTRACTED EACH YEAR. PEOPLE TOILED DAY AND NIGHT IN HARSH CONDITIONS - MANY OF THESE WERE FORCED LABOR WHO WERE PRISONERS FROM SWEDEN'S CONFLICTS WITH DENMARK, RUSSIA OR POLAND. WRITTEN SOURCES ALSO SHOW COMMON CRIMINAL CONVICTS FROM SWEDEN-FINLAND WERE ALSO EXPLOITED. KING ERIC, SON OF GUSTAV VASA, ORDERED THAT THE MOST DANGEROUS MINING WORK SHOULD BE DONE ONLY BY PRISONERS OF WAR. PRISONER DISCIPLINE WAS HARSH AND TWO MINE MANAGERS WERE CONDEMNED TO DEATH FOR GIVING PRISONERS TOO MUCH FREEDOM