Otto III. von Brandenburg, Margrave of Brandenburg, was born 1215 to Albrecht II. von Brandenburg (c1150-1220) and Mechthild von Lausitz (c1185-1255) and died 9 October 1267 of unspecified causes. He married Beatrix of Bohemia (c1231-1290) 1243 JL .
Children
| Name | Birth | Death | Joined with |
| Johann III. von Brandenburg (1244-1268) | |||
| Otto V. von Brandenburg (c1246-1298) | 1246 | 23 July 1298 | Judith von Henneberg (c1247-bef1295) |
| Albrecht III. von Brandenburg (c1250-1300) | 1246 | 23 July 1298 | Matilda of Denmark (1250-c1299) |
| Otto VI. von Brandenburg (c1255-1303) | |||
| Kunigunde von Brandenburg (-c1292) | 8 June 1292 | Bela of Slavonia (1245-1269) Walram V van Limburg (?-1279) | |
| Mathilde von Brandenburg (c1251-c1316) | 1251 | 1316 | Barnim I. von Pommern (c1210-1278) |
| Agnes von Brandenburg (c1260-bef1301) | 1260 | 1301 | Bolko I of Opole (bef1258-1313) |
Footnotes (including sources)
| ‡ General |
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