Since the conception of society, law enforcement bodies have existed to protect citizens from criminals or to maintain the status quo and keep leaders in power. Dating back to Biblical times, there were military personnel tasked to maintain peace and order. In Egypt, for example, a pharaoh ruled the land and soldiers chased the Israelites across the Red Sea. There were other societies with military hierarchies as well, like the Babylonian, the Syrian, and the Palestinian societies, among others.
The most prominent of all military organizations was that of the Roman Empire. They had a very effective and brutal form of law enforcement that they utilized to maintain peace and order. It was the Romans who introduced the infamous symbol of the crucifix. The Romans never really had an actual police organization. It was only in the fifth century that clan chiefs and heads of state were tasked to police the people under their care.
London was the first to hire paid enforcers back in 1663. Afterwards, the trend spread across the United Kingdom. It was only in June of 1800, that the authorities of Glasgow, Scotland were able to establish the City of Glasgow Police. They were the first professional police enforcers that practiced preventive policing. In 1829, the Metropolitan Police Act was passed by Parliament. This established the first civil police force and the model used by many countries today, including the United States. Outside of the United Kingdom, the Gibraltar Police was the first police service in 1830. In 1721, Spain formed Mossos d'Esuadra in Catalonia. In 1834, the Toronto Police was founded in Canada. It was one of the first police departments in North America. The first full-time police force in United States was the Boston Police Department in 1839.