That famous phrase, “an Englishman’s home is his castle”, neatly captures longstanding ideas about what the private home really is: a place which we can control and defend, a private territory where we decide who enters and who doesn’t. We all share a deep and primitive fear of intrusion and invasion, which lead us to see the home as a place of refuge.

So it seems strange that while crime has broadly declined over the past two decades across the Western world, we have also seen the appearance of many more gated communities and homes with extensive security systems.

In our new book, Domestic Fortress: Fear and the New Home Front we explore some of the explanations for this surprising trend. For one thing, withdrawal from public life has become something of an escapist fantasy, promoted by high-profile celebrities who use their wealth to pursue privacy. Think of Richard Branson’s island escape on Necker, the Barclay twins’ castle on Brecqhou in the Channel Islands, or Mark Zuckerberg’s purchase of neighbouring properties.

Read more: The fortress complex: how the West became obsessed with home security