Baldwin III was born , the son of Arnulf I, Count of Flanders and his second wife, Adele of Vermandois (c. 915 – 969). She was a daughter of Herbert II, Count of Vermandois. Baldwin became co-ruler of Flanders in 958 alongside his father Arnulf I. During his short rule, Baldwin was responsible for establishing the wool manufacturing industry at Ghent and markets at other towns in Flanders. Baldwin III died on 1 January 962 of smallpox. He was buried at the Abbey of Saint Bertin. 