There are five main reasons for choosing a particular city as the seat of government or as the capital city. The first is usually simply mass that's M. A. S. S. the capital of the nation is usually the city with the largest population and the most economic activity. London is a good example of this however, some countries choose to do things differently. A second reason is geographical compromise, usually between two competing centres of the nation. Canberra in Australia is exactly half way between the two big cities Sydney and Melbourne both of which wanted political power. Wellington in New Zealand is the middle point between the north and south islands was some countries ethnical compromise is more important, Abuja in Nigeria is very small compared to Laos but it was chosen because it doesn't have any strong ethnic ties. Then of course there's safety, when Canada chose Ottawa as the capital in eighteen fifty nine, Montreal had recently been burnt down in social unrest. Quebec was considered unstable and Toronto was too close to the United States border. Finally, the last reason might be simply economic, the construction of Brasilia was an attempt to develop the economy in the underpopulated Amazon basin.