Heinsberg

The lords of Heinsberg sprang from the House of Wassenberg: in 1082 Goswin, brother of the first count of Guelders, was invested with the lordship around Heinsberg west of the Rhine. Philip of Heinsberg, Archbishop of Cologne from 1167 to 1191, became Duke of Westphalia in 1180, built the Cologne city wall and died during Emperor Henry VI's siege of Naples.

After the male Wassenberg line failed, the heiress Alix married a younger son of the count of Cleves in 1168, and her daughter Agnes carried Heinsberg to the Sponheim family. Theodoric of Heinsberg, son of Godfrey II, inherited Loon and Chiny through his mother in 1336 and held them against the claims of Liege.

His only son died on the Prussian Crusade in 1342. After Theodoric's death in 1361, the disputed inheritance of Loon and Chiny sparked the War of the Loon Succession; Heinsberg later passed to the dukes of Juelich.