He conformed to the established religion (Anglican) to progress politically,[1] and became Commissioner for Ecclesiastical Causes, imposing the Reformation on Dublin.
This led to the conflict with his mother, Margaret Ball, whom he imprisoned for recusancy in Dublin Castle, where she endured conditions of appalling squalor for four years.
Despite protests from other family members, especially his brother Nicholas, Walter defended his actions, arguing that he had shown clemency by sparing his mother's life, and that she could free herself by swearing the Oath of Supremacy (although it was almost impossible for a Roman Catholic to do this in good conscience).
He remained implacable and during his brother's term as Mayor managed to thwart his efforts to free their mother.
His widow remarried Dr. Robert Conway, Master in Chancery, who died in 1602, and then Sir John Elliott, Baron of the Court of Exchequer (Ireland), who outlived her.