John Christian was eleven-years old and his younger brother George Rudolf was only seven, the regency of the Duchies was taken by their mother, the Dowager Duchess Anna Maria (who held Oława as her dower).

During some time, John Christian live in Krosno Odrzańskie (German: Crossen an der Oder), where he met his first wife, Dorothea Sybille of Brandenburg.

Then, the brothers decided to make the division of their lands: John Christian retained Brzeg, Oława, Strzelin, Niemcza, Kluczbork and Byczyna, and George Rudolf came into possession of Legnica, Wołów, Złotoryja, Grodźca, Lubin, Prochowice, Wińsko, Wąsosz, Ryczeń and Rudna.

The brothers followed the example their second-cousin, John Sigismund, Elector of Brandenburg, who shortly before publicly took communion according to the Calvinist rite, after almost two years of professed in secret.

In Silesia John Christian persuaded several nobles to join to the Anti-Habsburg side, promising military support.

However, the cruelty and dictatorial government of Frederick V, the Silesians began to reject the Anti-Habsburg moods and they fading totally on 8 November 1620, when at the Battle of White Mountain were the Habsburg army severely defeated the Bohemian forces.

Standing all the time faithfully at the side of Frederick V, John Christian urged to the Silesian states to adopt a tax on the continuation of the war.

In addition, Ferdinand II received the sum of 300,000 guilders for participants in the revolt, with the exception of the chief of the Silesian forced, Duke John George of Krnov.

In the next year, at the Northwestern, came the Imperial army under the command of Hans Ulrich von Schaffgotsch, husband of John Christian's sister, Barbara Agnes.

John Christian was accused of allowing the access of the Saxon armies to Brzeg; the Imperial troops invaded his Duchy, and the Duke, his family and court were forced to fled.

On 20 October 1633 John Christian arrived to Toruń, where he rented a house, after obtaining the prior consent of the King Wladyslaw IV Vasa to move to Poland.

In 1635 Ferdinand II entrusted the government of Brzeg to John Christian's oldest son George III as administrator.

On 4 October 1636, and after obtaining the consent of George William of Brandenburg, John Christian assumed the direct administration over Ostróda, where he remained with his family until his death.

The young bride (she had fifteen years) was a relative of John VI of Sitzsch, who during 1600–1608 held the dignity of Bishop of Wrocław and Imperial Governor of Silesia.

Eighteen months later, on 7 December 1627, Emperor Ferdinand II gave an Imperial Diploma raised Anna Hedwig to the rank of Baroness (German: Freiherrin), and two months later, on 18 February 1628, by a similar act in Regensburg the Emperor issued for the oldest son of John Christian and Anna Hedwig, August, the title of Baron of Legnica (German: Freiherr von Liegnitz), and the same title was secured for the future children of the couple.