The Sulzbach line was related to the Palatinate-Neuburg line, who were the Electors of Palatine. When the Elector of the Palatinate, Charles III Philip failed to produce a male heir, Joseph Charles (1694-1729), the eldest son of the Count Palatine of Sulzbach became the heir apparent. On the 2 May 1717 Joseph Charles married Charles III Philip's daughter, Countess Palatine Elizabeth Augusta Sophie of Neuburg, in a match intended to unite the two lines and prevent another war of succession. However, all the sons born to the couple died in infancy and in 1728 Elizabeth Augusta died in childbirth, followed by her husband the following year. Therefore, the inheritance of the Palatinate-Sulzbach passed to Joseph Charles' brother, John Christian Joseph and his family.