Euphemia Piast of Masovia was born 1310 to Trojden I of Masovia (c1285-1341) and Maria Yuryevna of Halych (c1292-1341) and died after 1373 of unspecified causes. She married Casimir I of Cieszyn (c1285-1358) 1321 JL .
Children
| Name | Birth | Death | Joined with |
| Anna of Cieszyn (1325-1367) | |||
| Władysław of Cieszyn (c1328-1355) | |||
| Jolanta of Cieszyn (c1331-1403) | |||
| Bolesław of Cieszyn (c1332-1356) | |||
| Przemysław I Noszak of Cieszyn (c1334-1410) | 1334 | 23 May 1410 | Elisabeth of Bytom (c1348-1374) |
| Agnes of Cieszyn (1338-1371) | |||
| Jan of Cieszyn (c1339-c1359) | |||
| Siemowit of Cieszyn (c1340-1391) | |||
| Elisabeth of Cieszyn (c1341-c1364) | |||
| Name | Birth | Death | Joined with |
| Son of Masovia (c1362-bef1378) | |||
| Son of Masovia (c1363-bef1378) | |||
| Henry of Masovia (c1369–c1392) | |||
Residences
Footnotes (including sources)
| ‡ General |