He was one of twelve Oxford scholars appointed at the suggestion of convocation in 1411 to inquire into the doctrines of Wycliffe.
[citation needed] On 17 November 1421 he was appointed by papal provision to the see of Rochester, and was consecrated on 7 June 1422[1] at Canterbury by Archbishop Chicheley.
After his consecration he appears among the royal councillors, and after 1430 his name constantly occurs among those present at the meetings.
On 18 February 1434 he had licence to absent himself from the council if sent on a mission by the pope or cardinals, and on 3 November of that year was appointed to treat for the reformation of the church and peace with France.
[1] It is commonly alleged that Langdon's body was brought home for burial at the Charterhouse, Loudon, but in reality he was interred in the choir of the Carthusian monastery at Basle.