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====Summary====

The role of Prime Minister is historical because it represents the earliest form of modern government headed by an individual who was not a monarch. Defining this role has not always been clear, with the position of Prime Minister not even formally declared for several centuries. Increasingly, however, prime ministers were needed as kings lost power in Europe and elsewhere. With the increasing influence of Britain in the 19th century, the post-Prime Minister became a position commonly seen in governments around the world. However, what it means to be Prime Minister continues to evolve today, with some countries opting to combine presidential and parliamentary systems, as each has different advantages in selecting leaders.

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