As the UK’s domestic jihadist threat enters its fourth decade, the threat picture is one that is radically transformed from its early days. Drawing on information from just under 70 separate plots in the UK since 1998, this paper sketches out the changing nature of the external threat picture, the nature of the individuals involved in the plots and the sorts of attacks that they were planning. Given the relatively limited space and discursive nature of the set thesis, the piece is necessarily superficial in some ways, but sketches out a trajectory in the threat picture in the UK. The paper breaks the time period down into four separate phases (1998-2004; 2004-2009; 2009-2013; 2013-2018), which capture four distinct moments in the nature of the violent Islamist terrorist threat to the UK. In concluding, it observes that the arc of threat has shifted from the UK being a launchpad for threats abroad, to a threat picture which is characterized by lone-actor style plots with greater inspiration, rather than clear direction, from foreign groups.