Pope Urban VI conferred the See of Salisbury on Waltham on 3 April 1388, and he was consecrated Bishop of Salisbury on 20 September 1388 at a ceremony attended by King Richard II. During his reign as bishop, Waltham challenged the authority of the Archbishop of Canterbury, William Courtenay, by refusing a canonical visitation in 1390; threatened with a sentence of excommunication by Courtenay, Waltham submitted. At this time, the teachings of John Wycliffe and the Lollards were gaining popularity, and to suppress this movement, Waltham compelled the mayor and city of Salisbury to submit to the episcopal court and to prohibit conventicle meetings.