1. A method of event processing, said method comprising the steps of: providing an event processing pattern language; extending said event processing pattern language to support historical patterns thereby enabling a user to define patterns comprised of both on-line streaming and retrospective historical patterns utilizing a single pattern language; and wherein said steps of providing and extending are implemented in either of computer hardware configured to perform said providing and extending steps, and computer software embodied in a non-transitory, tangible, computer-readable storage medium.