He was the eldest son of John II of Werle and Matilda of Brunswick.
In 1347, they split their inheritance, with Bernard II receiving Werle-Waren and Nicholas III retaining the smaller Werle-Güstrow.
He is last mentioned in a document dated 10 August 1360 and probably died a short time later.
Nicholas married on 6 January 1338 Agnes (1320–1340), daughter of Lord Henry II of Mecklenburg.
They had two children: After 1341, he married Matilda, daughter of Count John III of Holstein-Plön.