He was the youngest son of John II of Werle [-Güstrow] and his wife Matilda of Brunswick-Grubenhagen.
After the death of his father John II in 1337, his brother Nicholas III ruled Werle alone, until Bernard came of age in 1339.
On 14 June 1347, Werle was divided, with Bernard taking Werle-Waren.
In 1374, John IV of Werle-Goldberg died, and Bernard inherited his territory.
He married in 1341 with Elisabeth (died between 1391 and 1410), a daughter of Count John "the Mild" of the Holstein-Plön.