Nielsen Hayden genealogy
Descendants of Siemowit I of Masovia
![Male](img/tng_male.gif)
Father: Konrad I of Masovia
(Between 1187 and 1188 - 31 Aug 1247)
![Locate Person in Chart, Link to Ancestor Chart & Descendant Chart](img/rrtextplus_locate.gif)
Mother: Agafia Svjatoslava of Novgorod
( - Aft 31 Aug 1247)
![Locate Person in Chart, Link to Ancestor Chart & Descendant Chart](img/rrtextplus_locate.gif)
Siemowit I of Masovia (Abt 1228 - 23 Jun 1262)
    :       └─ Euphemia of Masovia
(Abt 1310 - Aft 1373 bur.Cieszyn, Silesia, Poland) =>
![Locate Person in Chart, Link to Ancestor Chart & Descendant Chart](img/rrtextplus_locate.gif)
    :        + Casimir I of Silesia
(Between 1276 and 1280 - Aft 21 Sep 1358 bur.Cieszyn, Silesia, Poland)
    :        (m. Between 1321 and 1324)
![Locate Person in Chart, Link to Ancestor Chart & Descendant Chart](img/rrtextplus_locate.gif)
    :        (m. Between 1321 and 1324)
            + Heinrich III of Silesia
(Between 1312 and 1321 -
            13 Apr 1369 bur.Augustinian Cloister, Zagan, Zagan, Silesia, Poland)(m. Bef 6 Sep 1337)
![Locate Person in Chart, Link to Ancestor Chart & Descendant Chart](img/rrtextplus_locate.gif)
            13 Apr 1369 bur.Augustinian Cloister, Zagan, Zagan, Silesia, Poland)(m. Bef 6 Sep 1337)