Behaviour event monitoring system for a vehicle

A system for monitoring events in the vicinity of a vehicle 12 comprises one or more controllers 15 configured to receive behaviour data relating to a body 34 external to the vehicle 12. The behaviour data is compared with predetermined behaviour data, and further data (relating to the behaviour data) is output for communication to one or more entities. The External body 34 may be another vehicle. The behaviour data may relate to an image, speed, proximity, heading, or angle. The predetermined behaviour data may be a maximum speed threshold, (user selectable) minimum separation threshold or a heading angle threshold. The one or more entities may be another vehicle, a remote server and/or a law enforcement service. Image data may include a number plate. A user may be able to select a body external to the vehicle, for which the system is to receive behaviour data and make a behaviour comparison.