Probably due to the influence of Dunstan, the Archbishop of Canterbury (959–988), Ælfheah was elected Bishop of Winchester in 984, and was consecrated on 19 October that year. While bishop he was largely responsible for the construction of a large organ in the cathedral, audible from over a mile (1600 m) away and said to require more than 24 men to operate. He also built and enlarged the city's churches, and promoted the cult of Swithun and his own predecessor, Æthelwold of Winchester. One act promoting Æthelwold's cult was the translation of Æthelwold's body to a new tomb in the cathedral at Winchester, which Ælfheah presided over on 10 September 996.