This paper addresses the nature and functions of command systems in major sudden impact disasters such as earthquakes. It discusses the bases of emergency command, including the lead agency concept and the support function principle. It reviews various models of co-ordination and control, including the Incident Command System (ICS) and the strategic-tactical-operational approach. With regard to the impact of modern information and communications technology, the paper discusses emergency command processes in relation to how emergency situations are perceived. It goes on to examine popular support for disaster management with respect to how the response to disasters can be democratised, especially with regard to the general transition from military to civilian forms of command. This debate is further developed with respect to overseas humanitarian operations and the transfer of know-how to countries that are in the early stages of developing their civil protection systems. The paper ends by restating the objectives of emergency command and considering possible future trends in this critically important field.