The remainder of his life was spent on his estate of Klein-Öls (today Oleśnica Mała, Poland) in Silesia, a gift of the king.
As a Teutonic Knight, Siemowit was successively named komturem of Oleśnica Mała near Oława since 1360, Prior of Poland, Bohemia, Moravia, Austria, Styria and Carinthia since 1372 and Governor and Treasurer of the Order in Germany since 1384.
Oleśnica | Oleśnica Mała | Oleśnica County | Wioska, Oleśnica County | Sadków, Oleśnica County | Mała Panew | Ligota Wielka, Oleśnica County | Ligota Mała, Oleśnica County | Ligota Mała, Dzierżoniów County |