sentences:  The Teutonic Order was called to the Culmerland in 1226 by Konrad I of Masovia, who started a number of attacks and crusades against the Prussians and later asked the Knights to protect him from retaliatory raids by the Prussians.Preoccupied with crusades in the Holy Land, the Teutonic Knights arrived only in 1230.Their first task was to build a base on the left bank of Vistula at Vogelsang, opposite of Toruń (Thorn), which was completed a year later.