castle which was at Borgloon during the middle ages. His son Arnold II, Count of Loon, founded the Abbey of Averbode. The son and heir of Arnold II was Louis (Dutch Lodewijk) I. He founded Averbode Abbey by charter dated 1135, and was count of Loon, Stadtgraf of Mainz, and count of Rieneck, both in modern Germany. He increased Loon's territory adding Kolmont (now in Tongeren) together with Bilzen. He strengthened the fort there and gave the city freedoms. He also did the same in Brustem (now in St Truiden), which came under threat as a Loon enclave surrounded by the County of Duras. Count Gerard (sometimes incorrectly called Gerard "II"), the next count of Loon and Rieneck, fortified Brustem and Kolmont, and moved the capital of the county to Kuringen. There he founded Herkenrode Abbey, for women living according to the Cistercian rule. In Loon, the enduring conflict with his Liège overlords culminated in an 1179 campaign by Prince-Bishop Rudolf of Zähringen, whose troops devastated the county's capital at Borgloon in 1179. In 1193 he also acquired the county of Duras and advocacy of the abbey of Sint-Truiden, but had to accept Brabant's suzerainty over those lands. This area gave power over abbey lands in Sint-Truiden, Halen, and Herk de Stad, effectively defining what is today still the southwestern border of Belgian Limburg. Gerard's son Louis II was heir, but Rieneck went to another son, Gerard, Count of Rieneck. The counties of Rieneck and Loon were re-united eventually under Gerard of Rieneck's son Louis III of Loon, but he then divided them again, giving Loon to his brother Arnold IV. By marriage, Count Arnold IV acquired the French-speaking County of Chiny in 1227, and brought the main line of the counts of Loon to the high point of its territorial expansion. The comital male line became extinct with the death of Louis IV of Loon in 1336 and the Loon and Chiny estates were at first inherited by the noble House of Sponheim at Heinsberg with the consent of the Liège bishop. In 1362 Prince-Bishop Engelbert III of the Marck nevertheless seized Loon and finally incorporated it into the Liège territory in 1366. The county remained a separate entity (quartier) within Liège, whose prince-bishops assumed the comital title. When the bishopric was annexed by Revolutionary France in 1795, the county of Loon was also disbanded and an adjusted version