specific way to refer to governments which work for the public good. In medieval Northern Italy, a number of city states had commune or signoria based governments. In the late Middle Ages, writers such as Giovanni Villani began writing about the nature of these states and the differences from other types of regime. They used terms such as libertas populi, a free people, to describe the states. The terminology changed in the 15th century as the renewed interest in the writings of Ancient Rome caused writers to prefer using classical terminology. To describe non-monarchical states, writers (most importantly, Leonardo Bruni) adopted the Latin phrase res publica. While Bruni and Machiavelli used the term to describe the states of Northern Italy, which were not monarchies, the term res publica has a set of interrelated meanings in the original Latin. The term can quite literally be translated as "public matter". It was most often used by Roman writers to refer to the state and government, even during the period of the Roman Empire. In subsequent centuries, the English word "commonwealth" came to be used as a translation of res publica, and its use in English was comparable to how the Romans used the term res publica. Notably, during The Protectorate of Oliver Cromwell the word commonwealth was the most common term to call the new monarchless state, but the word republic was also in common use. Likewise, in Polish the term was translated as rzeczpospolita, although the translation is now only used with respect to Poland. Presently, the term "republic" commonly means a system of government which derives its power from the people rather than from another basis, such as heredity or divine right. History While the philosophical terminology developed in classical Greece and Rome, as already noted by Aristotle there was already a long history of city states with a wide variety of constitutions, not only in Greece but also in the Middle East. After the classical period, during the Middle Ages, many free cities developed again, such as Venice. Classical republics The modern type of "republic" itself is different from any type of state found in the classical world. Nevertheless, there are a number of states of the classical era that are today still called republics. This includes ancient Athens and the Roman Republic. While the structure and governance of these states was different from that of any modern republic,