His elder brother, John, succeeded to Cliffe Hall, while three of his other brothers were also ordained to the priesthood: Thomas was Superior of the English Seminary in Paris, Robert was President of English College, Douai, and Anthony was a Douai priest, who fell into ill health and retired to serve the convent of the Poor Clares in Rouen.
In their letter to the Propaganda Fide, dated 20 October 1694, they commissioned Witham to serve as their agent for English matters with the authorities in Rome.
He was also recommended to the Propaganda Fide by a letter from James II & VII, the exiled king of England and Scotland.
[5] It had been intended for Witham to succeed as the Vicar Apostolic of the London District,[6] following the death of John Leyburn in 1702.
[10] He died in office at Cliffe Hall on 16 April 1725, aged 69,[1] and was buried at All Saints' Church, Manfield, near Darlington.