Arnold of Altena, count of Altena, count of Isenberg and Hövel, Vogt of Werden (1166–1209) was son of Eberhard IV of Berg. He inherited the north-western territorium of Altena, and became 1st count of Isenberg in 1200.
He married Mechtild countess of Holland and Styrum, a daughter of Floris III, Count of Holland. They had issue:
Eberhard II count of Altena and Isenberg (born 1180, died 1209)Friedrich II of Isenberg, count of Altena and Isenberg (d. beheaded at Cologne 13 Nov 1226);Dietrich of Altena, Prince-Bishop of Münster (born before 1180, died on the way back from Rome to Limburg 18 Jul 1226);Engelbert of Altena, Prince-Bishop of Osnabrück (1224-deposed 1226 following his implication in Engelbert II of Berg's assassination, rehabilitated 1238-1250) (born before 1200, died 1250);Philipp of Altena, Propst zu Soest and Domthesaurar in Cologne (born before 1200, died 1264);Bruno of Altena, Prince-Bishop of Osnabrück (1250–1259) (born before 1200, died 20 December 1258);Gottfried of Altena, Probst zu St. Martin and Domdechant in Münster (born before 1220, died after 1247);Adolf von Holte (born 1220, died before 25 Jan. 1260), married to Elisabeth von Holte (died after 1260). They had issue:Heinrich von Holte, a prior in Cologne (fl. 1261/89);Arnold von Holte, a priest (fl. 1266);Wilhelm von Holte, a priest (fl. 1281);Mechtild von Holte, heiress of Holte and Morenhoven (died 1301), married to Gerhard von Arberg, Bggf von Köln (d. 1287);Heilwig (fl. 1237/46), married to Wilhelm I von Horn; andChristina (fl. 1257), married to Albero Schalle;Wilhelm of Altena, also called Wilhelm of Isenberg (1223-1242). He had a son, Wilhelm (fl. 1275), married to Christina NN;NN, a daughter, married to Hermann of Altena.Agnes of Altena, a daughter, married to Christian III, Count of Oldenburg.Genealogische Handbuch des Adels, Gräfliche Häuser A Band II, 1955;W. Gf v. Limburg Stirum, "Stamtafel der Graven van Limburg Stirum", 's Gravenhage 1878;A.M.H.J. Stokvis, "Manuel d'Histoire, de Genealogie et de Chronologie de tous les États du Globe", Tome III, Leiden 1890-93;W. K. Prins v. Isenburg, "Stammtafeln zur Geschichte der Europaischen Staaten", 2. Aufl., Marburg/Lahn, 1953.
