Why did great britain and france want colonies?

Great Britain and France wanted colonies because:

Might: Having large amounts of colonies spread throughout the world showed that the country was extremely strong (need of superior troops), wealthy (to transport people and materials) and have a strong leadership
Resources: Having more colonies generally meant more resources. More resources meant that the country can continue with their technological advances and run the country mush more easily.
Population: The more population means that they can tax the people (more governmental income), and even call on the people to join the army in war.

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