I am a historian of Britain and the English-speaking world since the middle ages. My next book What is Free Speech? The History of a Dangerous Idea will be published in 2025 by Penguin Random House and Harvard University Press. I am writing the first-ever biography of the 18th-century Black Jamaican polymath Francis Williams (c. 1690–1762), based on newly discovered sources.

I have previously published on various other topics, and especially on the history of changing sexual attitudes and behavior. My book The Origins of Sex: A History of the First Sexual Revolution tells the story of the Enlightenment origins of modern western attitudes to sex. It drew on pictorial, fictional, judicial, philosophical, and other kinds of evidence, and tried to connect together social, intellectual, literary, legal, political, and other kinds of history.

I am strongly committed to public engagement and the communication of historical scholarship to as wide an audience as possible, through writing for the press, broadcasting, and public speaking. You can find out more at my website.

Before coming to Princeton in 2016, I spent many years on the Faculty at Oxford, where I am now a life fellow of All Souls College and of Exeter College. I was educated at Oxford, York, and Amsterdam.

During the academic year 2024-25 I am on sabbatical leave at Cambridge University and the V&A Museum in London.