Sachsenkriege Karls des Großen
Formerly part of the Saxon stem duchy along with Angria and Eastphalia, the Westphalian lands were Christianized by the Cologne archbishops at the behest of the Frankish ruler Charlemagne upon his conquests in the Saxon Wars. First parishes were established east of the Rhenish estates around Soest, where the archbishops extended their episcopal territory. Numerous monastery foundations, like Grafschaft Abbey in 1072 by Anno II of Cologne, stabilized the ecclesiastical rule.