On 20 February 1536 John married Christina Catherine of Schidlowitz (Polish: Krystyna Katarzyna Szydłowiecka; 1519–1556).

In a joint deed dated 25 June 1535, they awarded the city of Srebrna Góra, which belonged to Münsterberg, the status of free mining town.

In 1542, Joachim and his brothers pledged the heavily indebted Duchy of Münsterberg to their uncle Duke Frederick II of Legnica.

After the death of his first wife he married on 8 September 1561 with Margarete, a daughter of Duke Henry II of Brunswick-Wolfenbüttel who survived John by fifteen years.

John's son, Charles Christopher died in 1569 after a brief reign as Duke of Münsterberg at the age of 24 years.