The aim of this research was to see whether the groups/cells and their 38 core individuals who had taken part in the six most serious terrorist conspiracies and attacks in the UK between 2004 and 2007, all of which were driven by the ideology of violent Jihadism as espoused by Al Qaeda, exhibited any specific types of behaviour. In each case the terrorists successfully launched or unsuccessfully attempted an attack, or were arrested and convicted of conspiring to carry out a terrorist attack. The research provides a detailed examination of the behaviours exhibited by violent Jihadist groups/cells and the individuals within them.