This article outlines the need for a sustained investigation into London's relationship with terrorism. Drawing on recent critiques of security studies, and challenging histories of London's violence, the article demands that we prioritize an analytical approach centred upon terrorism's spatial impact. London's built environment is loaded with symbolic resonances (from imperialism to neo-colonialism, institutional power to high finance), all of which have made (and make) this city a recurrent target for terrorism. Crucial to this reading of the city is an awareness of London's transnational circuitrythat is, how violence committed in London is tethered to violence enacted abroad. By understanding terrorism through these spatial politics, it also becomes possible to isolate London as the historic origin of a new form of terrorist violenceone orientated around place alienation as opposed to targeted assassination. This shift can be located in the nineteenth century and connected to technological advances. It is this conjunction between terrorism and urban modernity that has been a constant refrain in London's development.