This introductory chapter sets the context for the discussions in subsequent chapters by analysing some literature on conceptualising vulnerability, as well as examining the types of individuals and groups now defined as Vulnerable. There are many and varied definitions on this very contentious and politically charged concept, and historically different individuals and groups have been categorised as Vulnerable from different professional, policy and academic perspectives. The concept of vulnerability is very complex with fleeting contours and is expressed differently in the USA, Europe and China. In the practice chapter, with contribution written from the perspective of professionals working in Ambulance, Police and Fire and Rescue services, the findings do indeed confirm the challenging nature of front-line service delivery, as all services are coping with increasing demands from Vulnerable people.