Wolfgang was born on 6 April 1531 in Herzberg, the fifth son of Duke Philip I of Brunswick-Grubenhagen and his second wife, Catherine of Mansfeld.
Like most of his predecessors, he had financial problems, so he was often forced to sell or pledge major parts of his possession and he had to demand high taxes.
He attempted to improve the educational level in his country by establishing a court school in Herzberg.
In the same year, he confirmed the Harz mining regulations of 1554 and gave Herzberg citizens the right to brew beer and a licence to trade wine.
Wolfgang died on 14 May 1595 in Herzberg and was buried next to his parents, brothers and wife in the crypt of the St. Giles Church in Osterode am Harz.