Oleśnica

Oleśnica was a Silesian duchy ruled in 1337 by the Piast duke Konrad I. In 1329 he had sworn allegiance to King John of Bohemia to resist rival claims.

His successors acquired Koźle in 1355, but Hussite forces overran the duchy in 1432. After Konrad X died in 1492, it passed to the Poděbrad family in 1495 and to Silvius Nimrod of Württemberg in 1647. Prussia took Silesia in 1742, and the duchy passed to the Welf dukes in 1792.