This document provides a history of emergency medical services (EMS) from ancient times to modern day. It discusses the evolution of EMS from the Good Samaritan and Knights Hospitaller in ancient times, through wartime medical services in the Napoleonic Wars and American Civil War. It then outlines the development of modern civilian EMS systems in the 20th century, including the establishment of government services, fire-based and hospital-based EMS, as well as private and air medical services. The document concludes by looking at challenges facing today's EMS such as overcrowded emergency rooms, ambulance waiting times, and new ideas and protocols being explored to address these issues.