Appointed by letters patent in March 2015,[2] he was designated acting Clerk upon the retirement of Sir Robert Rogers in August 2014.

[5] He was educated at Eton, Trinity College, Cambridge, and Harvard University, where he was a Kennedy Scholar.

Following a controversial recruitment process, Bercow proposed the selection of Carol Mills, then secretary of the Department of Parliamentary Services in the Parliament of Australia, for the job of Clerk of the House and Chief Executive, sending the formal nomination to the Prime Minister with the request that it be passed to the Sovereign, who makes the appointment by letters patent.

[3] In a letter to the Speaker of the House of Commons on 14 November 2018 Natzler announced his intention to retire on 1 March 2019.

[12] In the 2018 Birthday Honours, Natzler was appointed Knight Commander of the Order of the Bath (KCB) for parliamentary service.