Nielsen Hayden genealogy
Descendants of Otto I of Brandenburg
Abt 1126 - 1184 (~ 57 years)Father: Albrecht of Saxony (1100 - 18 Nov 1170)
Mother: Sophia von Winzenburg ( - 8 Jun 1160)
Otto I of Brandenburg (Abt 21 Jun 1126 - 7 Mar 1184)
   └─ Albrecht II of Brandenburg (Abt 1177 - 25 Feb 1220)
    Mathilde von Nieder-Lausitz ( - 1255)(m. Aug 1205)
       ├─ Matilde von Brandenburg (Abt 1210 - 10 Jun 1261)
       │ Otto I of Brunswick-Lüneburg (1204 - 19 Jun 1252)
       │    ├─ Adelheid of Brunswick-Lüneburg ( - 12 Jun 1274) =>
       │    │ + Heinrich I von Hessen (24 Jun 1244 - 21 Dec 1308)(m. Bef 10 Sep 1263)
       │    │ + Wizlaw II of Rügen (1240 - 29 Dec 1302)(m. Between 1263 and 1265)
       │    ├─ Helene of Brunswick-Lüneburg (18 Mar 1223 - 6 Sep 1273) =>
       │    │ + Albrecht I of Saxony (Abt 1180 - 8 Nov 1261)(m. Between 1247 and 1248)
       │     + Alessina de Monferrato ( - 5 Feb 1285)(m. 1 Nov 1266)
       ├─ Johann I of Brandenburg (1213 - 4 Apr 1266)
       │ Sophie of Denmark (1217 - 2 Nov 1247 Flensburg, Schleswig-Holstein, Germany)(m. 1236)
       │ :   └─ Konrad I (Between 1236 and 1245 - Between 15 Mar 1304 and 21 May 1304) =>
       │ :    + Konstancja of Poland (Between 1245 and 1246 - 10 Oct 1281)(m. 1260)
       │ Jutta of Saxony ( - 23 Dec 1287)(m. 7 May 1255)
       │    ├─ Agnes of Brandenburg (Between 1256 and 1261 - Oct 1304 bur.Ringsted, Denmark) =>
       │    │ + Eric V Klipping, King of Denmark (1249 Lolland, Denmark - 22 Nov 1286 Finderup, Viborg, Denmark)
       │    │ (m. 11 Nov 1273)
       │    │ (m. 11 Nov 1273)
       │    └─ Heinrich I of Brandenburg (Abt 1260 -
       │     14 Feb 1318 bur.Chorin Cloister, Chorin, Brandenburg, Germany) =>
       │     14 Feb 1318 bur.Chorin Cloister, Chorin, Brandenburg, Germany) =>
       │     + Agnes of Bavaria (Between 1276 and 1278 - 22 Jul 1345 Sangerhausen, Saxony-Anhalt, Germany)
       │     (m. Aft Nov 1298 Nürnberg, Bavaria, Germany)
       │     (m. Aft Nov 1298 Nürnberg, Bavaria, Germany)
       └─ Otto III of Brandenburg (Abt 1215 - 9 Oct 1267)
        Beatrix of Bohemia ( - 25 May 1286)(m. Jan 1243)
           │ + Jutta von Henneberg ( - Bef 13 Sep 1295)(m. 22 Oct 1268)
           └─ Mathilde von Brandenburg (Between 1248 and 1255 - 20 Dec 1316) =>
            + Barnim I of Pomerania (Between 1210 and 1218 - Abt 13 Nov 1278)(m. Bef 20 May 1267)