In 1226, Duke Konrad I of Masovia invited the Teutonic Knights to help him fight the pagan, Baltic Old Prussians, who lived in a territory adjacent to his lands; substantial border warfare was taking place and Konrad's province was suffering from Prussian invasions. On the other hand, the Old Prussians themselves were at that time being subjected to increasingly forced, but largely ineffective Christianization efforts, including Northern Crusades sponsored by the papacy. The Teutonic Order soon overstepped their authority and moved beyond the area granted them by Konrad (Chełmno Land or Kulmerland). In the following decades, they conquered large areas along the Baltic Sea coast and established their own monastic state. As virtually all of the Western Baltic pagans became converted or exterminated (the Prussian conquests were completed by 1283), the Knights confronted Poland and Lithuania, then the last pagan state in Europe. Teutonic wars with Poland and Lithuania continued for most of the 14th and 15th centuries. The Teutonic state in Prussia, increasingly populated by German settlers beginning in the 13th century, but still retaining a majority Baltic population, had been claimed as a fief and protected by the popes and Holy Roman Emperors.