What is the political reason for having colonies?

There are several political reasons a nation might want to have colonies.

The first is simple: power. When a nation founds a colony, they acquire power over a new region and the people in it. This might mean the colonizing nation lives as an upper class in the new area. It might mean taking slaves.

The second reason is related: wealth. Yes, that’s technically an economic reason, but you can’t separate these. When a nation...

There are several political reasons a nation might want to have colonies.

The first is simple: power. When a nation founds a colony, they acquire power over a new region and the people in it. This might mean the colonizing nation lives as an upper class in the new area. It might mean taking slaves.

The second reason is related: wealth. Yes, that’s technically an economic reason, but you can’t separate these. When a nation develops considerable new wealth, it has immediate political consequences. If you find gold or silver, you can hire mercenaries.  I

A third reason slides over into culture: a nation might think it has some duty or obligation to colonize an area that comes from non-political sources. Some aspects of the colonization of the Americas were religious: Christians wanted to bring their religion to new lands.

A fourth reason moves back into politics, but in a more subtle fashion. Nations found colonies to change their existing situation. This might mean starting trade, as was the case with ancient Greek colonies. It might mean gaining a place for ships to stop and restock. England used Australia as a penal colony, sending criminals (and others who disrupted society) far away, to keep  the peace at home.