During his father's reign, Joachim Frederick wasn't included in the government of the Duchy of Brzeg. He spent seven years at the court of his maternal uncle, John George, since 1571 Elector of Brandenburg. As a representative of Brandenburg, Joachim Frederick appeared at the coronation of Henry of France as King of Poland in 1574, and in the coronation of King Rudolf II in Rome on 27 October 1575. Two years later, he received a dowry of 15,000 talers secured for the town of Wąsosz on occasion of his marriage with Anna Maria of Anhalt.
Duke of Oława-Wołów
George II died on 7 May 1586. Joachim Frederick, together with his younger brother John George took the government of Oława and Wołów but not in Brzeg, who was given by the late Duke to his widow Barbara of Brandenburg as dower. When John George died on 6 July 1592 without surviving issue, Joachim Frederick became in the sole ruler of all their domains, except the two main cities of Brzeg and Oława. However, two events changed this situation: on 24 October 1594 Anna remarried with Duke Frederick IV of Legnica, followed two months later by the death of Barbara, on 2 January 1595. Joachim Frederick reunited all the paternal heritage under his rule. His Duchy also expanded thanks of the districts of Dzierżoniów and Srebrna Góra, who had rich deposits of precious metals. Also, in 1596 he inherited Legnica after the death of Duke Frederick IV without surviving issue.
Government and functions
Joachim Frederick was an efficient ruler. He ratified the former privileges of his cities and supported the development of crafts. In Oława he built fortifications and opened mints, thanks to the mines of Dzierżoniów and Srebrna Góra. Also, he established a pension for the unmarried daughter of the deposed Henry XI of Legnica. Thanks to his family connections and his good relations with the Prague court, he held honorable functions. Since 1585 he held the dignity of Lutheran Provost of the Chapter of Magdeburg, and in 1588 was appointed the General Commander of the Regular Army of Silesia.
Death
Joachim Frederick died on 25 March 1602 in Brzeg. On 7 May, he was buried in the local church of St. Hedwig. Under his will, wrote on 16 December 1595, he gave the district of Oława to his wife as dower. He was succeeded by his two surviving sons, John Christian and George Rudolf. Since both are minors at that time, the regency was exercised, firstly by their mother Anna Maria, and after her death in 1605, by their uncle Charles II of Poděbrady, Duke of Ziębice-Oleśnica.
