Since ancient times, earthquakes have taken a heavy toll on human life and property, made worse on a psychological level by the unexpected nature of the event. Mitigation of the damage caused by earthquakes is a prime requirement in many parts of the world today. As part of the design process, assessment of seismic loading is of fundamental importance and is the key step before any building design activity can be undertaken. Generally this also requires the assessment of an appropriate structural loading. Much effort has been devoted in the last fifty years towards understanding the causes of earthquakes and defining the loading on buildings associated with such events. Great advances have been made in the field of plate tectonics followed by developments in geotechnical engineering and soil mechanics. Though much remains to be followed up and quantified, understanding in these areas has reached a stage where the findings and procedures may now be integrated into a rational determination of ‘earthquake loadings’ for the design of structures.