Friedrich von Isenberg, Graf von Isenberg, auch Friedrich de Novus Ponte genannt (* vor 1193; † 14. November 1226 in Köln), war Sohn von Arnold von Altena, dem Grafen von Altena († nach 1205) und Mechthild von Holland (andere Quellen nennen auch Mathilde von Holland oder Mathilde von Cleve als Ehefrau^[1]). Sein Stammsitz war die Burg Isenberg bei Hattingen. Er ließ seinen Onkel 2. Grades Engelbert I. von Berg, den Erzbischof von Köln, am 7. November 1225 in einem Hohlweg im heutigen Gevelsberg von Gefolgsleuten überfallen. Wegen dessen Todes wurde er festgenommen und hingerichtet.

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http://fmg.ac/Projects/MedLands/FRANCONIA%20(LOWER%20RHINE).htm

FRIEDRICH [II] von Altena, son of ARNOLD Graf von Altena und Hövel & his wife Mechtild --- (-executed Köln 14 Nov 1226).  Levoldus’s mid-14th century Chronica Comitum de Marka records that “filius eius Fredericus comes de Hysenberch” succeeded “Everhardo comiti” [error for “Arnoldo”][59].  Graf von Altena und Isenberg.  The Chronicle of Alberic de Trois-Fontaines records that "archiepiscopus Coloniensis Engelbertus" was killed "1225 VII Id Nov" by "cognato suo Frederico comite de Ysenberg"[60].  The Chronica MinorAuctore Minorita Erphordiensi records that "Engilbertus Coloniensis archiepiscopus" was killed in 1225 by "comite Friderico de Ysinburg"[61].  The Chronicle of Alberic de Trois-Fontaines records that "Fredericus" fled to Rome, returned disguised as a merchant but was recognised and captured at Liège, and brought to Köln where he was executed by being attached to a wheel[62].  

m ([1210]) SOPHIE van Limburg, daughter of WALERAN III Duke of Limburg & his firstwife Cunégonde de Lorraine (-[1226/27]).  Levoldus’s mid-14th century Chronica Comitum de Marka records that “Fredericus comes de Hysenberch”married “sororem Henrici ducis Limburgensis”[63].  Her parentage is confirmed by the charter dated 1242 under which her son "Theodericus dominus de Isenberg" declared having surrendered "allodium castri…Limburgsupra Lenan" to "domino et avunculo meo Henrico comite de Monte", and having been regranted it as a fief[64].  A charter dated 24 Aug 1244 also confirms her parentage, recording that "Theoderici filii sororis ducis de Lymborch" renewed his allegiance to "domini Henrici ducis de Lymborch et comitis de Monte" for the recently constructed "castro Lynborch"[65].  The primary source which confirms her name has not yet been identified.   The Continuatio of the Chronicon Lamberti Parvi records the death in 1225 of "Galerannus dux Ardennæ et filia eius uxor Frederici proditoris ludificatione dæmonum cum parvulo filio"[66].  

Friedrich [II] & his wife had six children:  

1.         DIETRICH [I] (-1301).  His parentage is confirmed by the charter dated 1243 which records an agreement between "Engelbertus…Osnabrugensis episcopus, Henricus dux de Limburg comes de Monte" and "comitem Adolphum de Marka" to settle their dispute about the inheritance of "Theodericus de Isenburg consanguineus noster" received from "patris sui…comitis Friderici", which names "Theodericum et Fridericum fratres de Isenberg…tres etiam sorores Theoderici de Isenberg"[67].  Graf von Altena, Isenberg und Limburg.  

-        GRAFEN von LIMBURG, HERREN von STIRUM, HERREN von LIMBURG gt von STIRUM.  

2.         FRIEDRICH (-after 1243).  His parentage is confirmed by the charter dated 1243 which records an agreement between "Engelbertus…Osnabrugensis episcopus, Henricus dux de Limburg comes de Monte" and "comitem Adolphum de Marka" to settle their dispute about the inheritance of "Theodericus de Isenburg consanguineus noster" received from "patris sui…comitis Friderici", which names "Theodericum et Fridericum fratres de Isenberg…tres etiam sorores Theoderici de Isenberg"[68].  

3.         SOPHIE ([1211/26]-after 1291).  Her parentage and marriage are confirmed by the charter dated 24 Oct 1244 under which "Theodoricus de Isenberg" committed not to dispose of "castro de Limburg supra Lenam" without the consent of "avunculi mei ducis de Lymborch et comitis de Monte", at the request of "sororius meus dominus Henricus de Volmuntstene"[69].  “Theodoricus nobilis de Volmotstene” donated “decimam de...Werminge” to Kloster Scheda, with the consent of “matris meæ domine Sophyæ et fratrum meorum Everhardi, Walraveni, Hermanni, Adolphi, Engelberti, Frederici, Henrici”, by charter dated 25 Mar [1257/58][70].  “Theodericus de Volmodstene miles” confirmed that “Arturus de Sveve” had sold property to Kloster Oelinghausen, with the consent of “uxoris mee Lise et filii mei Bertoldi primogeniti et ceterorum liberorum meorum”, by charter dated 15 Aug 1269, sealed by “domini etavunculi mei Theoderici comitis de Ysenberg et matris mee Sophie”[71]. “Sophia senior domina de Volmestene relicta quondam domini de Volmestene bone memorie...Henrici” donated property to Kloster Herdicke, with the consent of “nostrorum filiorum Theoderici domini de Volmestene ac Hinrici fratris sui”, by charter dated 1291[72].  m as his second wife, HEINRICH [III] von Volmestein, son of --- (-before 7 May 1250).  

4.         ELISABETH (-after 1275).  "Dominus Theodericus vir nobilis de Murse" sold property in “Vorst” to Meer abbey, with the consent of “Elysabeth uxoris sue et liberorum suorem quos nunc habet...Theoderico, Friderico, Henrico, Ricolfo et Gerardo”, by charter dated 13 Jul 1259[73].  m([1234]) DIETRICH [I] Graf von Mörs, son of --- (-after 13 Jul 1259).  

5.         son (-[1226]).  The Continuatio of the Chronicon Lamberti Parvi records the death in 1225 of "Galerannus dux Ardennæ et filia eius uxor Frederici proditoris ludificatione dæmonum cum parvulo filio"[74].  

6.         AGNES (before 1226-after 12 Dec 1282).  Her parentage and marriage are confirmed by the charter dated May 1251 under which "Theodericus comes de Lymburg” donated property “in Vuspich” to Saarn abbey, sealed by “mariti sororis nostre viri nobilis domini B. de Bruke”[75].  Her relationship with the Altena/Limburg family is also indicated by the charter dated 1291 under which "Theodericus comes de Lymburg” donated property “apud Styrhem dicta uppen Brinke” to Saarn abbey, after the mediation of [her son] “domino Theoderico nobili de Bruke nostro consanguineo...”[76].  "Theodericus dominus de Bruka” confirmed that Camp abbey owned certain property, with the consent of “domine Agnetis matris nostre...Burchardi, Frederici,Walrami et Adolfi fratrum...et sororum nostrarum...Agnetis, Sophie et Adale”, by charter dated 19 Nov 1274[77].  "Theodericus vir nobilis dominus de Bruyche miles, Agnes mater eius, Walramus, Adolfus fratres eiusdem, Aleidis, Adela, Agnes et Sophia sorores, liberi et heredes dicte Agnetis et eius mariti quondam domini de Bruychge" sold land "Rode...in parrochia Owenheim" to the Teutonic Knightsat Köln by charter dated 12 Dec 1282[78].  m (before May 1251) BURKHARD [III] Herr von Broich, son of --- (-before 19 Nov 1274).  

FRIEDRICH [II] (-executed Köln 14 Nov 1226).  Levoldus’s mid-14th century Chronica Comitum de Marka records that “filius eius Fredericus comes de Hysenberch” succeeded “Everhardo comiti” [error for “Arnoldo”][22].  Graf von Altena und Isenberg.